Nickel is mainly used in electroplating industry, and the goods with nickel plating are beautiful, clean and hard to corrosion. It is very thin nickel powder, which is commonly used as the catalyst in chemical industry. Nickel is mostly used in manufacturing alloys. The mechanical strength can be improved by adding nickel to the steel. For instance, when the amount of nickel in the steel increased from 2.94% to 7.04%, the tensile strength will increase from 52.2 kg / mm 2 to 72.8 kg / mm 3.
Nickel steel is used to manufacture machine, which is mostly the parts withstanding larger pressure, impact and reciprocating load, such as turbine blades, crankshaft, and connecting rod and so on. The nickel steel containing 36% nickel , 0.3-0.5% carbon, whose expansion coefficient is very small, almost no thermal expansion and contraction, so it's often used in the manufacture of a variety of precision machinery, precision gauges etc.. The high nickel steel containing nickel 46% and carbon 0.15% is called "Platinum", because its expansion coefficient is similar to platinum, this kind of high nickel steel can be welded to the glass.
It is very important in the production of lamp, which can be used as a substitute for platinum wire. Some sophisticated lens frame also made of this type of platinum steel, and the lens can't fall from the frame because of thermal expansion and contraction. The alloy composed of 67.5% nickel, 16% iron, 15% chromium, 1.5% Mn has great resistance, so it's often used to make all kinds of varistors and electric heaters.
Titanium nickel alloy has the ability of memory, and the memory ability is very strong, after a long time, repeat 10 million times are accurate. Its "memory" ability is to remember its original shape, so people call it "shape memory alloy" ". This alloy had a characteristic transformation temperature, and it had an organization structure over the change temperature, it would have another structure below the change temperature. Different structure will have different performance. For example: a kind of titanium nickel memory alloy, it's very hard, and its intensity is very strong when its temperature is over the transition temperature, on the contrary, it is very soft, easy cold processing if its temperature is below this temperature. Therefore, when we need it to remember what shape, we can put it into that shape, this is the "permanent memory" shape, below the transition temperature, due to it is very soft, we can in a considerable extent to any deformation. And when it is restored to the original shape, we should just heat it to the transition temperature.
