What are Nonferrous metals?
Nonferrous metals do not contain any iron or metals that have an insignificant amount used as an alloy. Nonferrous metals are nonmagnetic. Standard nonferrous metals are aluminum, copper, lead, nickel, tin, and zinc, gold, and their alloys. Nonferrous metals have lower strength at high temperatures and more shrinkage than ferrous metals.
Advantages
Benefits of nonferrous metals are:
- Attractive colors
- Low density
- Excellent electrical conductivity
- Good thermal conductivity
- Easy to roll, forge, weld, cast, machine and fabricate
- High corrosion resistance
Uses and Properties of Nonferrous Metals
Property | Use |
---|---|
High Thermal Conductivity | Used in appliances, heating vessels, and heat exchangers |
High Electrical Conductivity | Used as an electrical conductor for various applications in many forms and shapes |
High Ductility | Can be easily spun, folded and cold worked. After cold working, it loses ductility and requires annealing |
Good Corrosion Resistance | Provides coatings on steel before chromium and nickel plating |
Welding Nonferrous Metals
There are many welding applications of nonferrous metals. However, the weldability varies and is different than when you are welding steel. Before welding review the procedures that are unique to each type of metal.
Aluminum (AI)
Aluminum has the symbol AI and is a chemical element in the boron group. It has the atomic number 13. It is malleable, gray-white-silver in color, nonmagnetic, soft, and ductile metal. It is easy to work with and has an attractive appearance.
How it is produced
Aluminum is produced by electrical processes from a clayey mineral known as bauxite.
Commercial aluminum alloys are classified into two groups:
- Wrought alloys: Includes those alloys designed for mill products whose final physical forms are obtained by working the metal mechanically.
- Cast alloys: Includes those alloys whose final shapes are obtained by allowing the molten metal to solidify in a mold.
Uses
- Household utensils and appliances
- Alloying agent and deoxidizer in steel manufacturing
- Castings
- Pistons
- Torque converter pump housings
- Aircraft structures
- Kitchen utensils
- Railways cars
- Transmission lines
Capabilities
Aluminum can be:
- cast
- forged
- machined
- formed
- welded
Limitations
Avoid direct contact of aluminum with copper alloys and copper. Use aluminum in low-temperature applications.
Properties
Aluminum is lightweight, soft, and a low-strength metal that needs alloys added to increase strength. Aluminum can be easily cast, forged, machined, formed, and welded.
Except when alloyed with specific elements, it is only for low-temperature applications.
- Corrosion Resistant
- High strength/weight ratio at room temperature
- Corrosion-resistant
- High electrical conductivity (Volume for volume, 60% of copper)
- Excellent thermal conductor
- Lightweight
- High ductility
- Needs to be frequently annealed if cold worked
- Hardens after cold
- Malleable
Aluminum Properties:
- Hardness: Pure aluminum has a Brinell hardness number of 17 to 27
- Strength: Aluminum has a tensile strength of 6000 to 16,000 psi (41,370 to 110,320 kPa)
- Gravity: specific gravity of 2.7
- Melting Point: The aluminum melting point is 1220°F (660°C)
-
Density @ 20oC: 2.702 g/cm3
Aluminum Alloy Properties:
- Hardness: Aluminum alloys have a Brinell hardness number of 100 to 130
- Strength: tensile strength of 30,000 to 75,000 psi (206,850 to 517,125 kPa).
Welding Aluminum
Aluminum can be welded using mechanical fastening, adhesive bonding, soldering, brazing, and welding (most common.)
Welding Processes that are used with aluminum:
- Arc Welding (most common)
- GTAW (gas tungsten arc welding)
- GMAW (gas shielded metal arc welding)
- Stud Welding
- Electron Beam Welding
- Laser Beam Welding
- Oxyfuel Gas Welding
- Resistance Welding
- Solid-state Welding
Identification Tests
- Appearance Test: Aluminum is silver to light gray and when polished is very bright. It gets dull when it becomes oxidized. It is also lightweight.
- Rolled sheet aluminum is typically usually pure metal
- Aluminum alloy castings are usually made with copper, zinc, silicon, and sometimes magnesium and iron
- Wrought aluminum alloys may contain manganese, magnesium, silicon or chromium
- Magnesium and aluminum are similar in appearance. Magnesium is distinguished from aluminum by applying on the surface a drop of silver nitrate solution. The silver nitrate does not react to the aluminum but leaves a black silver deposit on the magnesium.
- Fracture Test: A fracture in an aluminum casting shines a bright crystalline structure.
- Spark Test: No sparks are given off from aluminum.
- Torch Test: Before melting aluminum does not turn red. It holds its’ shape just before becoming molten. Once it does it then suddenly collapses (hot shorts). On the molten surface a heavy film of white oxide forms.
Aluminum Alloys
One or more metals are alloyed with Aluminum including nickel, silicon, manganese, magnesium, and copper. Aluminum is strengthened and hardened with small amounts of alloyed metals.
Aluminum Alloy | Composition | Characteristics | Uses |
---|---|---|---|
Duralumin | Copper (4%) Manganese (.5%) Magnesium (.5%) Iron (trace amount) | High Strength (similar to mild steel) Low Specific Gravity Lower Corrosion Resistance (when compared to pure aluminum) Strength increases with heat treatment and then aged for 3 to 4 weeks (called age hardening) For Corrosion Resistance thin aluminum film added to surface called Alclad) Heat worked at 500°C Cold worked after annealing and forging Light weight | Aircraft (Alclad) Forging Stamping Bars Tubes Rivets Automobile Industry |
Hindalium | Magnesium Chromium (small quantity) | Rolled (16 gauge) | Anodized Utensils |
Magnalium | Magnesium (2% to 10%) Manufactured when melted in a vacuum and then cooled under a pressure of 100 to 200 atmospheres. Copper (1.75%) | Light Weight Good Mechanical Characteristics | Automobiles, Aircraft Components |
Y-Alloy (also called Copper-Aluminum Alloy) | Aluminum (93%) Copper (2%) Nickel (1%) Magnesium (1%) | igh Strength Machinable Heat treated (quenching in boiling water at 510°C and age hardened for 5 days) Good mechanical characteristics Stronger than Duralumin at higher temperatures | Aircraft Cylinder Heads Aircraft Pistons Sheets Strips |
Aluminum vs. Copper
Aluminum has replaced copper due to its malleability and ductility, Particularly in appliances and for electrical transmission. When conducting heat and electricity, aluminum is not as good as copper.
Antimony (Sb)
Antimony is made from stibnite (also called antimonite.) It is a by-product of refining zinc, copper silver, or lead. Alloy in heavy metals such as copper, tin, and lead.
Uses and Properties
- Color: Silver white
- Hard
- Brittle (can be powdered)
- Very crystalline
- Melting Point: 1,167°F (630.6°C)
- Boiling Point: 2,888°F (1,587°C)
Brass and Bronze
Brass and bronze are copper alloys. As a copper alloy, they are corrosion resistant and good conductors of electricity and heat.
Brass
All Brass is an alloy of copper and zinc (60 to 68 percent copper and 32 to 40 percent zinc). It has high heat conductivity and a low melting point.
True Brass is an alloy of copper and zinc. It sometimes has additional alloys for specific properties. Several grades of strips and sheets are available.
Types of Brass:
There are several types of brass:
- Naval
- Red
- Admiralty
- Yellow
- Cartridge
- Muntz metal leaded
- Admiralty
- Nickel brass
- Commercial
- Afta-Betabrass: Contains 36% to 45% Zinc with the rest comprised of copper for hot work.
- Alfa Brass: Contains up to 36% Zinc with the remaining part copper for cold working.
All types vary in levels of zinc and copper. Each can be alloyed with other elements such as lead, tin, manganese, or iron. They have excellent machinability and can be welded.
Properties
- Ductility and tensile strength increases with the amount of Zinc (up to 30%)
- Different types can be cast, hot forged, cold-forged, cold-rolled into sheets, drawn into wires and extrusions for cross-section bars
- Beyond 30% Zinc, the tensile strength increases up to 45% of Zinc, but the ductility significantly drops. (β-phase is less ductile than α-phase, but it is stronger and harder
- Melting point: between 840°C to 960°C depending on the type of brass
- Machinability: Improves if 1% to 2% zinc is added
- Easily soldered
- Corrosion-resistant
Uses
- Bushes
- Bearings
- Utensils
- Pump linings
- Hydraulic fittings
Brass Vs. Copper
Brass has lower electrical conductivity and a lower thermal conductivity than copper. It is stronger than copper.
Welding Brass
The Zinc content in brass makes brass with a high concentration of Zinc harder to weld. The vaporization of Zinc during the welding process results in blowholes and incomplete fusion. It also degrades weldability and workability.
For this reason, choose a brass with a low concentration of Zinc. Processes for welding Brass are:
- GTAW (recommended to minimize zinc fuming)
- GMAW
Bronze
The name Bronze is currently applied to alloys of copper, tin, and any copper-based alloy that looks like bronze.
It may contain zinc, lead, nickel, phosphorus or manganese. It is corrosion-resistant, has good machinability, high strength and rust resistance.
Types of Bronze
Type of Bronze | Composition | Characteristics | Uses |
---|---|---|---|
Bell Metal | 20% to 21% Tin (20% to 21%) Remainder Copper | Resistant to surface wear Hard, easily cast | Utensils Gongs Casting Bells |
Gun Metal | Zinc (2%) Tin (10%) Copper (88%) | Adding lead improves casting, Adding zinc improves fluidity | Bearing bushes Glands Boiler fittings Pump valves |
Manganese Bronze | Manganese alloy (3.5%) Zinc (40%) Copper (60%) | Corrosion Resistance Harder and Stronger than Phosphor Bronze Poor response to cold working Not easily hot worked | Rods Plungers Feed Pumps Worm Gears Bushes |
Muntz Metal | Zinc (40%) Copper (60%) Possibility of Some Lead | When compared to normal brass it is more ductile, harder and stronger Between temperatures of 700°C to 750°C it does not respond to cold working | Architecture Machine Parts (when corrosion resistance is needed) |
Phosphor Bronze | Copper (93.6%) Tin (9%) Phosphorus (.1% to .3%) (varies by application) | High strength Ductility Improves Casting Soundness Good wearing qualities High Elasticity | Bearings (10% tin with some lead) Gears Nuts Machine lead screws Pump Parts Springs Linings |
Silicon Bronze | Silicon (3%) Manganese (1%) Copper (Remainder) | Corrosion Resistance High Strength (more than copper for both) Weldable (all methods) | Pressed (hot or cold) Stoves Forged Tanks Boiler Parts Stamped Cast rolled |
Welding
Bronze can be welded with differences between the different bronze alloys.
Bronze Alloy | Description | Welding Methods |
---|---|---|
Phosphor Bronze | Welding procedures need to minimize weld cracking. Hot peening is used to reduce welding stress and cracking. Welding. Preheating (150C to 250C) will improve metal fluidity. | GMAW (large fabrication and thick sections) GTAW for joining sheet metals (use helium or argon shielding) SMAW (with a ECuSn-C or ECuSn-A covered electrode) |
Aluminum Bronze | Use metals with more than 8% aluminum for better weldability because of finer crystal grains which contribute to lower susceptibility to cracks. | MAW GTAW (Argon shielding with AC current) SMAW (Use stringer beads and a short arc length - GMAW or GTAW are preferred) |
Silicon Bronze | Good Weldability due to low thermal conductivity. The metal is hot short. Not necessary to preheat. | GTAW GMAW SMAW |
Copper Composition
To be useful, Bronze contains 75% to 95% copper with the rest of the metal made up of tin. Higher levels of tin content result in higher strength and greater corrosion resistance (called hot working bronze).
Uses
- Alloy can be cold-rolled into sheets, rods, and wire
- Drawn and stamped products
- Rods
- Sheets
- Utensils
- Bushes
- Bearings
- Hydraulic fittings
Brass Vs. Bronze
Bronze has more corrosion resistance and better mechanical properties than brass.
Brass and Bronze Tests
- Appearance Tests: The color of polished bronze and brass varies with a shift from a red copper color to yellow brass. They oxidize to various shades of yellow, green, and brown.
- Fracture Test: The surface of fractured brass or bronze ranges from smooth to crystalline, depending upon composition and method of preparation (cast, rolled, or forged.)
- Spark Test: Sparks are not given off by brass and bronze.
- Torch Test: Brass contains zinc, which when melted gives off white fumes. Conversely, the metal Bronze has tin. A small amount of tin makes the alloy flow like water. Due to the small amount of zinc or tin that is usually present, bronze may fume slightly, but never as much as brass.
Aluminum Bronze Tests
- Appearance: When polished, aluminum bronze appears a darker yellow than brass.
- Fracture: When fractured, Aluminum Bronze has a smooth surface.
- Spark Test: No sparks are given off by aluminum bronze.
- Torch Test: It is tough to weld aluminum bronze. A difficult to remove scum covers the surface, and that mixes with the metal.
Cadmium (CD)
Cadmium is a by-product of lead and zinc. It is extremely toxic and frequently found in manufacturing.
Uses and Properties
- Color: White metal with a blue hue
- Can be polished
- Specific gravity is 8.67
- Melting point at 321°C
- Malleable
- Ductile
- Quickly drawn into wires and rolled
It is softer than zinc and harder than tin.
Chromium (Cr)
Chromium is an alloying agent used in steel, cast iron, and nonferrous alloys of nickel, copper, aluminum, and cobalt. It is hard, brittle, corrosion-resistant, can be forged, machined, welded, and electroplated. Chromium is not resistant to hydrochloric acid and cannot be used in its pure state because of its difficulty to work.
Uses
One of the most widely used alloys is chromium. In steel and cast iron it is used as an alloying agent (0.25 to 0.35 percent) and the nonferrous alloys of cobalt, copper, nickel, and aluminum. It is also used in powder metallurgy, electroplating for wear and appearance, and to make stainless steel and mirrors.
Capabilities
Chromium alloys can be forged, machined, and welded. Chromium is never used in its pure state.
Limitations
Chromium is brittle, making it difficult to work within a pure state. It is not resistant to hydrochloric acid.
Properties
- Specific gravity of 7.19
- Melting point of 3300°F (1816°C)
- Brinell hardness number of 110 to 170
- Resistant to acids other than hydrochloric, and is heat, wear, and corrosion-resistant.
Cobalt (Co)
Cobalt is a hard, white metal similar to nickel in appearance, but has a slightly bluish cast.
Uses
Cobalt does not have many uses in a metallic form. When combined with other elements, it is used for hard-facing materials. As an alloy Cobalt is mainly used in:
- permanent materials
- soft magnetic materials
- high-speed cutters and tool bits
- high-temperature, creep-resisting alloys
- cemented carbide tools, bits, and cutters
- used in making blue ceramic glazes and insoluble paint pigments
Capabilities
Cobalt can be machined (limited) welded, and cold-drawn.
Limitations
Cemented carbide cutters are used to machine Cobalt. Cracking can occur when welding high carbon cobalt steel.
Properties
- Tensile strength of 34,000 psi (234,430 kPa)
- Brinell hardness number of 125
- Specific gravity of 8.9
- Melting point of 2720°F (1493°C)
Cobalt Alloy (Stellite 21) Properties
- Tensile strength of 101,000 psi (696,395 kPa)
- Heat and corrosion-resistant.
Copper (Cu)
Copper is one of the most popular commercial metals. It is used with many alloys. It is frequently used as a protective coating for rods and sheets to make ball floats, containers, and soldering coppers.
Though it is very soft, it is tough to machine due to its high ductility and malleability.
Copper is a reddish metal and has high electrical and heat conductivity. It is used as a primary element in hundreds of alloys. Commercially pure copper is not suitable for welding.
Gas welding is the preferred process for joining copper and copper alloys and copper.
Types of Copper:
- Beryllium copper (1.50 to 2.75% beryllium): When hardened it gains in tensile strength but loses ductility. It is ductile when soft.
- Blister Copper: The crude form of copper is called Blister copper (68% pure).
- Pure Copper: With electrolytic refining, highly pure (99.9%) copper is remelted and cast into required shapes.
- Nickel-copper (Cupronickel): Contains either 10, 20, or 30 percent nickel. Nickel alloys have moderately high to high tensile strength, which increases with the nickel content. They are somewhat hard, quite tough, and ductile. They are very resistant to the erosive and corrosive effects of high-velocity seawater, stress corrosion, and corrosion fatigue. Some alloys are used for saltwater piping systems; other sheet forms are used to construct small storage tanks and hot water reservoirs. To avoid blowholes when welding use the filler metals of ERCuNi for GTAW and GMAW. If welding with SMAW use the filler metal ECuNi.
- Nickel Silver (Copper-Zinc Alloys): Nickel is added to copper zinc alloys (brasses) to lighten their color; the resultant alloys are called nickel silver. These alloys are of two general types:
- Contains 65 percent or more nickel and copper combined. Can be cold worked by such operations as deep drawing, stamping, and spinning.
- Contains 55 to 60 percent copper and nickel combined. The much harder end is not processed by any of the cold working methods.
Copper Welding
Copper and copper alloys are joined using soldering, brazing, and welding.
Welding processes used are:
- Arc Welding:
- GTAW (Gas Tungsten Arc Welding)
- GMAW (Gas Metal Arc Welding)
- SMAW (Shielded Metal Arc Welding, but only for non-critical applications)
- Electron Beam Welding
- Flash Welding
- Friction Welding
- Laser Welding
- Oxyfuel Gas Welding
- Pressure Welding
- Ultrasonic Welding
- Resistance Welding
Copper Uses
Commercially pure copper is primarily utilized in the electrical industry where it is made into electrical conductors such as wire.
Non-ferrous alloys such as bronze, brass, and Monel are manufactured using copper.
Other Uses
- Sheet roofing
- Cartridge cases
- Bushings
- Statues
- Bearings
- Wire
- Copper pipes
Capabilities
Copper is cast, cold worked, and forged. Machinability is fair, but copper and copper alloys can be welded with some limitations.
Limitations
There are welding limitations for electrolytic tough pitch copper. Pure copper is tough to machine due to ductility and is not suitable for welding.
Properties
- Nonmagnetic (Pure copper)
- Hardness: Brinell hardness number of 60 to 110
- Strength: Copper has a tensile strength of 32,000 to 60,000 psi (220,640 to 413,700 kPa).
- Copper alloys:
- Tensile strength: 50,000 to 90,000 psi (344,750 to 620,550 kPa)
- Brinell hardness: 100 to 185
- Gravity: It has a specific gravity of 8.9
- Melting Point: melting point of 1980°F (1082°C)
- Corrosion resistant.
Copper Tests
- Appearance: When polished, copper is red, it oxidizes to a green shade.
- Fracture Test: When fractured, copper as a smooth surface and does not have a crystalline appearance.
- Spark Test: No sparks are given off by Copper.
- Torch Test: Because copper conducts heat rapidly, a larger flame is required to fuse copper than is needed for the same quantity of steel. Copper solidifies instantly and melts suddenly. Copper alloy, which contains small amounts of other metals melts more easily and hardens more slowly than pure copper.
Lead (Pb)
Lead is a heavy metal (heaviest of all common metals) that is soft and malleable. It has a low melting point, creep strength and tensile strength. Lead extraction is from galena ore.
Color
The surface is bluish grayish in color, but after scratching or scraping it, the actual color of the metal appears white. When exposed to air it gets a very dull luster.
Capabilities
Lead can be machined, welded, cast, and cold worked. It is moisture, corrosion, atmosphere, and water resistant, and is resistant to many acids.
The correct welding rod selection is necessary due to a low melting point.
Limitations
Lead has low strength with a heavy weight. Lead dust and fumes are very poisonous.
Properties
- Pure Lead: Pure lead has a tensile strength of 2500 to 3000 psi (17,237.5 to 20,685 kPa); specific gravity of 11.3; and a melting point of 620°F (327°C).
- Alloy Lead: Alloy lead B32-467 has a tensile strength of 5800 psi (39,991 kPa). It is alloyed with steel and brass to improve machinability. It is also alloyed in plumbers and other solders.
General Properties
- Low electrical conductivity
- Self-lubricating
- Malleable; can be easily shaped and worked
- Corrosion resistant
- Chemical resistant (even many acids)
- Soft
- Heavy
Uses
Lead has more fields of application than any other metal.
- Electrical equipment (main use):
- lead-coated power
- electrical cables
- telephone cables
- storage batteries
- Building construction
- pipe and sheet form
- tanks
- roof coverings
- In solder
Uses of Lead-Zinc alloys:
- Utilized in the manufacture of:
- lead weights
- bearings
- gaskets
- seals
- bullets
- shot
- Chemical Compounds
- lead carbonate (paint pigment)
- tetraethyl lead (antiknock gasoline)
- X-ray protection (radiation shields)
Caution
Lead dust, fumes, and vapors are poisonous. Use care and protective safety equipment when welding lead.
Gold (Au)
Gold is a well-known nonferrous metal characterized by its distinct yellow color and exceptional properties. It is highly valued for its rarity, ductility, and resistance to corrosion. Gold has a melting point of 1,064°C (1,947°F) and a density of 19.3 g/cm³, making it one of the densest metals.
Applications: Gold is widely used in various industries due to its excellent conductivity and resistance to tarnish. In electronics, gold is used for reliable and long-lasting connections in devices such as smartphones and computers. The jewelry industry also extensively utilizes gold for crafting rings, necklaces, and other ornaments. Additionally, gold plays a critical role in finance, being a standard for currency and investment.
Properties:
- Chemical Symbol: Au
- Atomic Number: 79
- Density: 19.3 g/cm³
- Melting Point: 1,064°C (1,947°F)
- Conductivity: Excellent electrical and thermal conductivity
- Corrosion Resistance: High resistance to tarnish and corrosion
Gold and Welding
Gold, due to its unique properties, is not typically welded in the same manner as more common metals like steel or aluminum. However, welding techniques are sometimes employed when working with gold, particularly in the creation of intricate jewelry pieces. Gold’s high malleability and resistance to oxidation allow for precise joining processes without compromising the metal’s integrity.
Techniques such as laser welding are often used to join small gold components, ensuring strong, seamless bonds that maintain the metal’s desirable aesthetic qualities. In industrial applications, gold is rarely welded but can be used in conjunction with other metals that require welding, especially in electronics, where gold-plated connectors and contacts are common.
Gold Plating
Gold plating involves depositing a thin layer of gold onto the surface of another metal or alloy. This process is widely used in various industries, including electronics, jewelry, and decorative arts. Gold plating provides the appearance and some properties of solid gold, such as corrosion resistance and aesthetic appeal, without the high cost. Electroplating is the most common method, where an electric current is used to reduce gold ions onto the substrate. Plating or using a gold plating service is economical and versatile for covering larger surfaces or more intricate designs.
Gold’s unique properties and versatility make it an essential material in technology, luxury goods, and as a backstop for currency in financial markets.
Magnesium (Mg)
Magnesium has many useful properties. It is a very light metal (lighter than aluminum) making it easy to cast and machine. It is white in color, has a low melting point, excellent machinability, Magnesium has some moderate levels of resistance to atmospheric exposure, many chemicals such as alkalies, chromic and hydrofluoric acids, hydrocarbons, and most alcohols, phenols, esters, and oils. It is nonmagnetic. Galvanic corrosion is an important factor in any assembly with magnesium.
It is nonmagnetic. Galvanic corrosion is an important factor in any assembly with magnesium. Principal magnesium ores are dolomite, carnallite and magnesite. It is extracted using an electrolytic process.
Magnesium is moderately resistant to:
- atmospheric exposure
- chemicals such as:
- alkalies
- hydrofluoric acids and chromic acids
- hydrocarbons
- most alcohols
- phenols
- esters
- oils
Welding
Magnesium is weldable by either the arc or gas processes. It requires the use of a gaseous shield. It is welded on AC, but you want to weld them with the right filler metal.
Capabilities
Magnesium can be forged, cast, welded, and machined.
Limitations of Magnesium
Magnesium in fine chip form will ignite at low temperatures (800 to 1200°F (427 to 649°C)). The flame can be mothered with suitable materials such as carbon dioxide (CO2), foam, and sand.
Properties
Magnesium is the lightest metal. It weights two-thirds the weight of aluminum. The tensile strength of cast magnesium metal equals cast aluminum (90 MPa.) The tensile strength of rolled annealed magnesium is equal to quality cast iron.
Magnesium can be drawn forged, accurately machined and easily formed.
Powdered magnesium easily burns (use with fire protection and caution.)
- Tensile Strength: Pure magnesium has tensile strength of 12,000 psi (82,740 kPa) (cast) and tensile strength of 37,000 psi (255,115 kPa) (rolled)
- Hardness: Brinell hardness number of 30 (cast) and 50 (rolled)
- Gravity: Specific gravity of 1.7
- Melting Point: Melting point of 1202°F (650°C)
Magnesium Alloy Properties
- Hardness: Brinell hardness number of 72 (hard) and 50 (forged)
- Strength: Tensile strength of 42,000 psi (289,590 kPa) (hard) and 32,000 psi (220,640 kPa) (forged)
Uses
- Deoxidizer for bronze, brass silver and nickel
- Because of its light weight, it is used in many weight-saving applications, particularly in the aircraft industry.
- Used in the manufacture and use of fireworks for signals and railroad flares
- Magnesium casting has a good surface finish and is pressure tight making them ideal for this use. Uses are for engine housings, gearboxes, blowers, differential housings, hose pieces, landing wheels, portable tools, and certain parts of aircraft fuselage.
Magnesium alloy materials are used in sewing machines, typewriters, and textiles.
Magnesium Identification Tests
- Appearance Tests: Magnesium resembles aluminum in appearance. The polished surface is silver- white, but quickly oxidizes to a grayish film. Like aluminum, it is highly corrosion resistant and has a good strength-to-weight ratio, but is lighter in weight than aluminum. It has a very low kindling point and is not very weldable, except when it is alloyed with manganese and aluminum. Magnesium is distinguished from aluminum by the use of a silver nitrate solution. The solution does not react with aluminum but leaves a black deposit of silver on magnesium. Magnesium is produced in large quantities from sea water. It has excellent machinability, but special care must be used when machining because of its low kindling point.
- Fracture Test: Magnesium has a rough surface with a fine grain structure.
- Spark Test: No sparks are given off.
- Torch or Flame Test (Caution): Magnesium oxidizes rapidly when heated in open air, producing an oxide film which is insoluble in the liquid metal. A fire may result when magnesium is heated in the open atmosphere. As a safety precaution, magnesium should be melted in an atmosphere of inert gas.
Caution: Magnesium may ignite and burn when heated in the open atmosphere.
Manganese (Mn)
Pure manganese has a relatively high tensile strength but is very brittle. Manganese is used as an alloying agent in steel to deoxidize and desulfurize the metal. In metals other than steel, percentages of 1 to 15 percent manganese will increase the toughness and the hardenability of the metal involved.
Capabilities
Manganese can be welded, machined, and cold-worked.
Limitations
Austenitic manganese steels are best machined with cemented carbide, cobalt, and high-speed steel cutters.
Properties
- Tensile strength of 72,000 psi (496,440 kPa) (quenched)
- Brinell hardness number of 330
- Specific gravity of 7.43
- A melting point of 2270°F (1243°C); and is brittle. Manganese alloy has a tensile strength of 110,000 psi (758,450 kPa). Generally, manganese is highly polishable
- Brittle
Manganese alloy has a tensile strength of 110,000 psi (758,450 kPa).
Uses
Manganese is used mainly as an alloying agent in making steel to increase tensile strength. It is also added during the steel-making process to remove sulfur as a slag. Austenitic manganese steels are used for railroad trackwork, power shovel buckets, and rock crushers. Medium-carbon manganese steels are used to make car gears and axles.
Molybdenum (Mo)
Pure molybdenum has a high tensile strength and is very resistant to heat. It is principally used as an alloying agent in steel to increase strength, hardenability, and resistance to heat.
Capabilities
Molybdenum can be swaged, rolled, drawn, or machined.
Limitations
Molybdenum can only be welded by atomic hydrogen arc, or butt welded by resistance heating in a vacuum. It is attacked by nitric acid, hot sulfuric acid, and hot hydrochloric acid.
Properties
- Tensile strength of 100,000 psi (689,500 kPa) (sheet) and 30,000 Psi (206,850 kPa) (wire)
- Brinell hardness number of 160 to 185
- Specific gravity of 10.2
- Melting point of 4800°F (2649°C)
- Retains hardness and strength at high temperatures
- Corrosion-resistant.
Uses
Molybdenum is used mainly as an alloy. Heating elements, switches, contacts, thermocouples, welding electrodes, and cathode-ray tubes are made of molybdenum.
Monel
Monel metal is a nickel alloy of silver-white color containing about 67.00 percent nickel, 29.00 to 80.00 percent copper, 1.40 percent iron, 1.00 percent manganese, 0.10 percent silicon, and 0.15 percent carbon. In appearance, it resembles untarnished nickel. After use, or after contact with chemical solutions, the silver-white color takes on a yellow tinge, and some of the
After use, or after contact with chemical solutions, the silver-white color takes on a yellow tinge and some of the luster. It has a very high resistance to corrosion and can be welded.
Monel is harder and stronger than either nickel or copper; an acceptable substitute for steel in systems where corrosion resistance is the primary concern.
K-Monel vs. Monel
K-Monel was developed for greater strength and hardness than Monel; comparable to heat-treated steel; used for instrument parts that must resist corrosion.
Nickel (Ni)
Nickel is a hard, malleable, ductile tough metal. As an alloy, it will increase ductility, has no effect on grain size, lowers the critical point for heat treatment, aids fatigue strength, and increases impact values in low-temperature operations. Both nickel and nickel alloys are machinable and are readily welded by gas and arc methods.
85% of nickel is obtained from sulfide ores.
Color
The nickel color is silver
Capabilities
Nickel alloys are readily welded by either the gas or arc methods. Nickel alloys can be machined, forged, cast, and easily formed.
Limitations
Nickel oxidizes very slowly in the presence of moisture or corrosive gasses.
Properties
- Strength: Pure nickel has tensile strength of 46,000 psi (317,170 kPa)
- Hardness: Brinell hardness number 220
- Gravity: Specific gravity of 8.9
- Melting point of 2650°F (1454°C)
Alloy Properties
- Strength: Tensile strength of 100,000 psi (689,500 kPa), and high strength and toughness at high temperatures.
Nickel Alloys
Alloy | Composition | Characteristics | Uses |
---|---|---|---|
German Silver | Copper (60%) Nickel (30%) Nickel (10%) Zinc (10% | Silver Color Ductile Malleable | Costume Jewelry Taps Castings of high quality valves Electrical Contacts |
Monel Metal | Nickel (68%) Copper (30%) Iron (1%) Manganese (trace amount) | Corrosion Resistant Good Mechanical Properties (keeps them at high temperatures) | Aerospace Sea Water Exposure applications |
Incolony and Inconel | Nickel Chrome | Good mechanical properties at high temperatures Does not respond to heat treatment | Heat treating equipment Furnaces Gas-turbine components |
Nichrome | Chromium Iron Molybdenum Tin Carbon (small amount) | Heat Resistant | Electrical Wire |
Nickel vs. Copper
Nickel has more strength but less ductility than copper.
Uses
Nickel is used in making alloys of both ferrous and nonferrous metal.
- Food processing and chemical equipment due to resistance to both alkalis and acids
- Electrical resistance heating elements
- Ornamental trim
- Parts that must withstand elevated temperatures (produced from nickel-containing metal)
- Chromium alloys are used to make stainless steel
- Plated on steel to provide a layer or surface for corrosion resistance
- Steel alloy with high proportions of Nickel in Monel and Conel steel
Nickel Identification Tests
- Appearance: Pure nickel has a grayish-white
- Fracture: The fracture surface of nickel is smooth and fine-grained.
- Spark Test: In a spark test, nickel produces a very small amount of short, orange streaks which are generally wavy.
Tin (Sn)
Tin is used as an important alloy adding resistance to corrosion. Tin is a very soft, malleable, somewhat ductile, corrosion-resistant metal having low tensile strength and high crystalline structure. It is used in coating metals to prevent corrosion.
Color
Tin is brilliant white in color with a yellow tinge.
Capabilities
Tin can be die-cast, cold worked (extruded), machined, and soldered.
Limitations
Tin is not weldable.
Properties
- Strength: Pure tin has a tensile strength of 2800 psi (19,306 kPa)
- Gravity: Tin has a specific gravity of 7.29
- Melting Point: Tin has a melting point of 450°F (232°C)
- Corrosion-resistant
- Malleable
- Ductile
- Can be rolled in thin sheets
- Does not corrode in wet or dry conditions
Babbitt alloy tin has a tensile strength of 10,000 psi (68,950 kPa) and a Brinell hardness number of 30.
Uses
- Coating for steel
- Food preservation as tin foil
- As an alloying element
- With copper to produce tin brass and bronze
- With lead to produce solder
- With antimony and lead to form babbitt metal (Babbitt metal or bearing metal, is any of several alloys used for the bearing surface in a plain bearing.)
- Tinning of brass and copper wire before conversion into cables and brass utensils
- Useful protective coating for steel and iron and steel (due to corrosion-resistant properties)
- Alloys for solder
- Moisture-proof packing (thin sheets)
Tin Identification Tests
- Appearance: Tin is silvery-white in color.
- Fracture Test: The fracture surface of tin is silvery-white and fairly smooth.
- Spark Test: Tin gives off no sparks in a spark test.
- Torch Test: Tin melts at 450°F (232°C), and will boil under the torch.
Titanium (Ti)
Titanium and its alloys offer excellent corrosion resistance to acids, chlorides, and salt. Titanium falls into a family of metals called reactive metals, which means that they have a high affinity for oxygen.
Titanium is a very soft, silvery-white, medium-strength metal having very good corrosion resistance. It has a high strength to weight ratio, and its tensile strength increases as the temperature decreases. Titanium has low impact and creep strengths, as well as seizing tendencies, at temperatures above 800°F (427°C).
Capabilities
Titanium can be machined at low speeds and fast feeds; formal; spot-and seam- welded, and fusion-welded using an inert gas.
Limitations
Titanium has low impact strength, and low creep strength at high temperatures (above 800°F (427°C)). It can only be cast into simple shapes, and it cannot be welded by any gas welding process because of its high attraction for oxygen. Oxidation causes this metal to become quite brittle. The inert gas welding process is recommended to reduce the contamination of the weld metal.
Properties
- Tensile strength of 100,000 psi;
- Brinell hardness number of 200
- Specific gravity of 4.5
- Melting point of 3300°F (1851°C)
- Good corrosion resistance
Alloy titanium
- Brinell hardness number of 340
- Tensile strength of 150,000 psi
- High strength/weight ratio (twice that of an aluminum alloy at 400°F (204°C))
Uses
Titanium is a metal of the tin group which occurs naturally as titanium oxide or in other oxide forms. The free element is separated by heating the oxide with aluminum or by the electrolysis of the solution in calcium chloride. Its most important compound is titanium dioxide, which is used widely in welding electrode coatings. It is used as a stabilizer in stainless steel so that carbon will not be separated during the welding operation.
It is also used as an additive in alloying aluminum, copper, magnesium, steel, and nickel; making powder for fireworks; and in the manufacture of turbine blades, aircraft firewalls, engine nacelles, frame assemblies, ammunition tracks, and mortar base plates.
Titanium Metal Identification
- Appearance Test: Titanium is a soft, shiny, silvery-white metal burns in air and is the only element that burns in nitrogen. Titanium alloys look like steel and can be distinguished from steel by a copper sulfate The solution will not react with titanium but will leave a coating of copper on steel.
- Spark Test: The sparks given off are large, brilliant white, and of medium length.
Tungsten (W)
Tungsten is a hard, heavy, nonmagnetic metal that will melt at approximately 6150°F (3400°C).
Capabilities
Tungsten can be hot drawn and cold.
Limitations
Tungsten is hard to machine, requires high temperatures for melting, and is produced by powdered metallurgy (sintering process). Singering is the process of compacting and forming a solid mass of material by heat or pressure.
Properties
- Melting point of 6170 ± 35°F (3410 ± 19°C)
- Ductility
- Tensile strength of 105,000 psi (723,975 kPa)
- Specific gravity of 19.32
- Thermal conductivity of 0.397
- Brinell hardness number of 38
- Dull white color
Tungsten Uses
Tungsten is used in making:
- Light bulb filaments
- Phonograph needles
- As an alloying agent in the production of high-speed steel, and projectiles
- Alloying agent in:
- Non-consumable welding electrodes
- Armor plate
- Die and tool steels
- Hard metal carbide cutting tools
It is one of the first metallic nanoscale powders.
Tungsten Identification Tests
- Appearance: Tungsten has a steel gray color.
- Spark Test: In a spark test Tungsten produces a very small volume of short, straight, orange streaks.
Vanadium (V)
Occurs with the carbonaceous matter, free sulfur, and iron pyrite. The color is silvery white.
Uses and Properties
- Castings can be produced using non-ferrous alloys such as aluminum and copper.
- Used when manufacturing alloy steel
- Can be drawn into wires or hammered into any shape when heated to the appropriate temperature
- Melting Point: 1710°C
- Specific Gravity: 5.67
Zinc (Zn)
Zinc is a medium-low strength metal. It has a very low melting point and is somewhat heavy. Zinc is easy to machine but has a coarse grain.
Welding and Soldering
To prevent crystal cleavage, heat Zinc to about 180°F (82°C). If the heat input is controlled strictly and appropriately cleaned, Zinc can be soldered or welded.
Color
Blush-white
Capabilities
Zinc can be welded, machined, cast and cold worked (extruded).
Limitations
Do not use Zinc die castings in continuous contact with steam.
Properties of Zinc
- Strength: Zinc has a tensile strength of 12,000 psi (82,740 kPa) (cast) and 27,000 psi (186,165 kPa) (rolled)
- Gravity: Zinc has a specific gravity of 7.1
- Melting Point: Melting point of 790°F (421°C)
- Corrosion-resistant
- Brittle at 220°F (104°C)
- Boinging Point: The zinc boiling point is 940°C
Zinc Ores
- Blende (ZnS)
- Calamine (ZnCo3)
Other Forms
- Zinc oxide and zinc sulfide: Used in rubber and paint.
- Zinc dust: used to manufacture chemicals and explosives.
Zinc Uses
- Galvanizing metal: Zinc is used on iron or steel in the form of a protective coating called galvanizing or electroplating. It is the largest use of zinc and is done by dipping the part in molten zinc or by electroplating it. Examples of items made in this way are bolts, nails, galvanized pipe, sheet metal, tubing, and wire.
- Alloying Element: Zinc is used as an alloying element in producing alloys such as brass and bronze.
- Parts due to Low Melting Point and High Fluidity: Typical parts made with zinc alloy die castings, toys, ornaments, building equipment, carburetor and fuel pump bodies, instrument panels, wet and dry batteries, fuse plugs, pipe organ pipes, munitions, cooking utensils, and flux.
- Rolled Sheets: Used for non-corrosive container lining and roof covering.
Zinc Identification Tests
- Appearance: Zinc and Zinc alloys are blue-white when polished. When they oxidized they are gray in color.
- Fracture Test: Fractures from Zinc appear to be granular.
- Spark Test: Zinc alloys and Zinc give off no sparks in a spark test.
Zinc Die Castings Identification Tests
- Appearance: Die castings are usually alloys of zinc, aluminum, magnesium, lead, and tin. They are light in weight, generally silvery-white in color (like aluminum), and sometimes of intricate design. A die-cast surface is much smoother than that of a casting made in sand and is almost as smooth as a machined surface. Sometimes, die castings darkened by use may be mistaken for malleable iron when judged simply by looks, but the die casting is lighter in weight and softer.
- Fracture Test: The surface of zinc die casting is white and has a slight granular structure.
- Spark Test: No sparks are given off by Zinc die castings.
- Torch Test: Zinc die-castings can be recognized by their low melting temperatures. The metal boils when heated with the oxyacetylene flame. A die casting, after a thorough cleaning, can be welded with a carburizing flame using tin or aluminum solders as filler metal. If necessary, the die-cast part can be used as a pattern to make a new brass casting.
White Metal Die-Castings
These are usually made with alloys of aluminum, lead, magnesium, or tin. Except for those made of lead and tin, they are generally light in weight and are the color white.
White Metal Die Identification Tests
- Appearance Tests: The surface is smoother than casting made in the sand.
- Fracture Test: The fractured surface is white and somewhat granular.
- Spark Test: In a spark test no sparks are given off.
- Torch Test: The metal boils under the torch due to low melting points.
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References
“10 Facts about Barium | Fact File.” N.p., n.d. Web. 12 Feb. 2017.
“Chromium (cr): Maine Welding Company.” N.p., n.d. Web. 12 Feb. 2017