Nickel alloys are classified by application

① Nickel-based superalloy. The main alloying elements are chromium, tungsten, molybdenum, cobalt, aluminum, titanium, boron, zirconium and so on. Among them, chromium plays an anti-oxidation and anti-corrosion role, and other elements play a strengthening role. It has high strength, oxidation resistance and gas corrosion resistance at 650 ~ 1000℃, and is the most widely used and the highest high temperature strength alloy. It is used in the manufacture of high temperature components for aero engine blades and rocket engines, nuclear reactors, and energy conversion equipment.
② Nickel-based corrosion resistant alloy. The main alloying elements are copper, chromium and molybdenum. It has good comprehensive properties and can withstand various acid corrosion and stress corrosion. The earliest application is nickel-copper alloy, also known as Monel alloy; In addition, there are nickel chromium alloy, nickel molybdenum alloy, nickel chromium molybdenum alloy and so on. Used in the manufacture of various corrosion-resistant parts.
③ nickel-based wear resistant alloy. The main alloying elements are chromium, molybdenum, tungsten, but also contain small amounts of niobium, tantalum and indium. In addition to wear resistance, its oxidation resistance, corrosion resistance, welding performance is good. It can be used as a coating material, which can be coated on the surface of other base materials by surfacing welding and spraying process.
④ Nickel-based precision alloy. Including nickel-based soft magnetic alloy, nickel-based precision resistance alloy and nickel-based electric heating alloy. The most commonly used soft magnetic alloy is about 80% nickel permalloy, its maximum permeability and initial permeability is high, coercivity is low, is an important core material in the electronics industry. The main alloying elements of nickel-based precision resistance alloy are chromium, aluminum and copper. This alloy has high resistivity, low resistivity temperature coefficient and good corrosion resistance, and is used to make resistors. Nickel-based electrothermal alloy is a 20% chromium nickel alloy with good oxidation resistance and corrosion resistance, and can be used for a long time at 1000 ~ 1100℃.
⑤ Nickel-based shape memory alloy. Nickel alloy containing 50 (at) % titanium. The recovery temperature is 70℃, and the shape memory effect is good. A small change in the proportion of nickel-titanium components can make the recovery temperature change in the range of 30 ~ 100℃. It is widely used in the manufacture of automatic opening structural parts used in spacecraft, self-stimulating fasteners used in aerospace industry, artificial heart motors used in biomedicine, etc.