Nickel is a ferromagnetic metallic element that is highly polished and resistant to corrosion. Mainly used in alloys (such as nickel steel and nickel silver) and as catalysts (such as Lanay nickel, especially as a catalyst for hydrogenation), can be used to make money, etc., plated on other metals can prevent rust.

1, metal nickel is mainly used in electroplating industry, nickel plating articles beautiful, clean, and not easy to rust. A very fine nickel powder commonly used as a catalyst in the chemical industry.

2. Nickel is used in large quantities to make alloys. By adding nickel to steel, the mechanical strength can be improved. If the nickel content of steel increases from 2.94% to 7.04%, the tensile strength increases from 52.2 kg/mm 2 to 72.8 kg/mm 3. Nickel-steel is used to make parts of machines that withstand high pressure, impact and reciprocating loads, such as turbine blades, crankshafts, connecting rods, etc. Nickel containing 36%, carbon 0.3-0.5% nickel steel, its coefficient of expansion is very small, almost no thermal expansion cold contraction, used to manufacture a variety of precision machinery, accurate gauges. High-nickel steel with 46% nickel and 0.15% carbon is called "platinoid" because its coefficient of expansion is similar to platinum and glass. This high-nickel steel can be fused into glass. It is important in light bulb production and can be used as a substitute for platinum wire. Some precise transparent frames, also made of platinum-like steel, do not allow the lens to fall out of the frame as heat expands and cold contracts. An alloy composed of 67.5% nickel, 16% iron, 15% chromium and 1.5% manganese, with great resistance, used to make various rheostat and electric heaters.

3, titanium nickel alloy with "memory" ability, and memory is very strong, after a long time, repeat tens of millions of times are accurate. Its "memory" ability is to remember its original shape, so people call it "shape memory alloy". It turns out that this alloy has a characteristic transition temperature, above which it has one structure, and below which it has another structure. Different structure, different performance. For example, a titanium-nickel memory alloy is hard and strong when it is above the transition temperature, while it is soft and easy to cold work below this temperature. In this way, when we need it to remember a shape, we can make it into that shape, which is its "permanent memory" shape, below the transition temperature, and since it is soft, we can deform it to a considerable extent. And when it is needed to return to its original shape, it is simply heated above the transition temperature.

4. Nickel is magnetic and can be attracted by magnets. Alloys made of aluminium, cobalt and nickel are much more magnetic. When this alloy is attracted by an electromagnet, not only will it be drawn by itself, but something sixty times its weight will be hung under it without falling. In this way, it can be used to build electromagnetic cranes.

5. Nickel salts are mostly green. Nickel hydroxide is brownish black, and nickel oxide is gray-black. Nickel oxide is commonly used to make iron-nickel alkaline batteries.