Category: Metals and Alloys

Important nickel alloys are iconel and monel metals. The composition of iconel is 75% nickel, 15% chromium and 9% iron. Monel metal comprises two-thirds nickel, one-thirds copper with a small percentage of elements like iron, silicon, manganese and carbon. Iconel can be cast, forged, rolled and cold drawn. It has brittle behaviour when the temperature…

Magnesium alloys comprise 3–10% aluminium, 1–3.8% zinc and 0.4% manganese. The two important magnesium alloys are dow metal and electron metal. Dow metal comprises 9.1% magnesium and 9% aluminium. Electron metal, a trade name of magnesium, is a base alloy that contains 4% zinc and small percentages of copper, iron and silicon. The tensile strength…

Principal elements that are alloyed with pure aluminium to improve its tensile strength and hardness are copper, silicon, manganese, zinc, magnesium and nickel. Copper is the main hardening element for aluminium alloy by the addition of a small percentage of magnesium, which improves the hardness and strength after heat treatment. Similarly, the addition of a…

Two important principal classes of copper alloys are brass and bronze. Brass is primarily an alloy of copper and zinc, whereas bronze is a combination of copper and tin. Brasses are formed with 5–45% of zinc and copper. Brasses possess excellent mechanical properties. They are corrosion resistant and are readily machinable. The mechanical properties of…

Non-ferrous alloys may be defined as a coherent non-ferrous metallic mass produced by combining two or more non-ferrous metals. Some important non-ferrous alloys are discussed below.

Nickel is found combined with iron sulphides in deposits. The properties of nickel are as follows:

It occurs in nature in several minerals such as magnesite (MgCO3), dolomite (CaCO3, MgCO3), kieserite (MgSO4 · H2O) and carnalite (MgCl2 · KCl · 6H2O). The metal is prepared by the chloride or oxide process. The oxide process is not in use anymore. In the chloride process, a melted mixture of chlorides of sodium, potassium and magnesium…

Common ores of zinc are zincite (ZnO), calamine (ZnCO3) and zinc blende (ZnS). It is a bluish grey non-ferrous metal. It becomes brittle at a high temperature of 200°C and can also be powdered at this temperature. It is used in the form of a sheet as a corrosion-resistant surface. Further, it is also used…

The chief source of tin is tinstone (or cassiterite) SnO2. Tin is a bright shining white metal. It is soft and malleable and can be made into the form of thin foil. As it has high resistance to corrosion, it is used for coating purposes on metals and alloys. It is particularly used in low…

The lead ore is galena or galenite consists of lead sulphide. It is widely distributed. In the manufacturing process, the roasted ore, silica, coke, metallic iron and lime are smelted together in a blast furnace. Lead oxide and sulphate react with iron to form ferrous oxide and sulphate, resulting in the formation of lead. Ferrous…