Alloys of Nickel
Nickel alloys are tougher, stronger and harder than copper and aluminium alloys. These alloys are also very strong like steel. Alloys of nickel have high resistance to corrosion. It has also high resistance to scaling and oxidation at high temperature condition. MONEL is an alloy of nickel, copper and a little amount of manganese and aluminium. Nickel is around 60% and copper is around 30%. The alloy Monel is white in color. It is strong, tough, rustproof and highly resistant to corrosion. It is ductile and machinable. It is more resistant than nickel under the reducing conditions. It is more resistant to copper under the oxidizing conditions. It is highly resistant to corrosion by salt water, dilute sulphuric acid, organic acid and caustic soda. It is also resistant to brine, sodium sulphite, hydrochloric acid, phosphoric acid and chlorinated hydrocarbons. The alloy Monel has applications in oil refining, chemical industries, pulp industries and building constructions. It is used in making of turbine blades, pumps, valves, shafts and propellers. Addition of sulphur, carbon, iron and cobalt makes this alloy into increasing applications in making of specialized rods, tubes, wires, strips, surgical equipments and bearings. The alloy Monel can be grouped into 4 groups depending upon the variable presence of sulphur, carbon, iron and cobalt. These varieties are K-MONEL, H-MONEL, R-MONEL and S-MONEL.
German silver is an alloy of copper, nickel and zinc. It is hard and ductile. It is found in bright silvery color. German silver also shows high resistance to corrosion. It is used for utensils, decorative items and electrical equipments. It is also used in ornaments. Nickel-Silicon is a casting alloy. It is very strong, tough and hard. It is resistant to corrosion of acids and alkalis. It is used in reaction vessels, mixers, pipes and sanitary fittings. It is also used in electrical wires and filaments. Nichrome is an alloy of nickel, iron and chromium. It is used in the production of resistance wire for electrical equipments. It is also used for rheostats of electronic equipments. Nichrome has good resistance to oxidation, scaling, heat fatigue and carborizing gases. It is used for furnace parts, heating equipments and carborizing containers.
Inconel is an important alloy of nickel, chromium and iron. The content of nickel is 75-80% and chromium content is 10-15%. The remaining potion is taken by iron. Inconel is used for parts and equipments those are exposed to high temperature conditions for extended period. It is less reactive with acids. Inconel combines the corrosion resistance, strength and toughness of nickel along with resistance to oxidation of chromium. It resists the attack of caustic soda, hot fatty acid, dilute hydrochloric acid, nitric acid and other oxidizing liquids. This alloy can withstand repeated heating and pulling variation within temperature range of 0'-870'C. It is used in aeroplane engines, electrical heating equipments, fire boxes, brine tanks, diary equipments and food processing equipments. It is used in heaters and condensers in the chemical industries. It is also used in springs, thermocouple- protection tubes, retorts, carburizing boxes and nitriding containers. Inconel X is an alloy of nickel, cobalt, chromium, iron and aluminum. It is highly resistant to oxidation at high temperature. It is used for gas turbine, super chargers and jet propulsion engines. Due to its special applications, it is called as a super alloy.
Nickel, molybdenum and iron alloy is known as Haste alloy. It can be cold work to increase hardness. It is used in the cast as well as wrought form. It is used in chemical industries to handle acids and corrosive materials. It is also used for agitators, mixers, driers, condensers, heat exchangers and evaporators. Nimonics is a new type of nickel alloy. It is having nickel, chromium, cobalt, molybdenum, titanium and aluminum as its constituents. It is used as container for highly oxidizing agents, chlorines and some acids. It is also used in jet engines, turbine blades and furnace equipments. It is useful under high temperature conditions and high corrosive conditions.