Nickel alloy seamless tube titanium nickel alloy has "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 the alloy has a characteristic transition temperature, above which it has one structure, and below which it has another. Different structure, different performance. A ti-ni memory alloy, for example, is hard and strong above the transition temperature, and soft and easy to cold work below. So, when we need it to remember any shape, we make it that shape, and this is its "memory" shape, below the transition temperature, and because it's so soft, we can deform it to a considerable degree. And when it needs to return to its original shape, just heat it above the transition temperature.

Nickel is magnetic and is attracted to a magnet. Alloys made of aluminum, cobalt and nickel are even more magnetic. When the alloy is attracted by an electromagnet, it not only sucks itself in, but also hangs under it sixty times its weight without falling off. In this way, it can be used to make electromagnetic cranes.

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