(1) metal material
Metal materials are the most important engineering materials, including metals and metal-based alloys. Metals and their alloys are divided into two parts in industry:
1. Ferrous metal materials: iron and iron-based alloys (steel, cast iron and ferroalloy).
2. Non-ferrous materials: all metals except ferrous metals and their alloys.
The most widely used is ferrous metal. Iron-based alloy materials account for more than 90.0% of the whole structural materials and tool materials. Ferrous metal material has become the most important engineering metal material because of its superior engineering performance and low price.
Nonferrous metals can be divided into light metals, fusible metals, refractory metals, precious metals, rare earth metals and alkaline earth metals according to their properties and characteristics. They are important materials with special uses.
(2) Non-metallic materials
Non-metallic materials are also important engineering materials. Including refractory materials, refractory insulation materials, corrosion-resistant (acid) nonmetallic materials and ceramic materials.
(3) Polymer materials
Polymer materials are organic synthetic materials, also known as polymers. It has excellent properties such as high strength, good plasticity, strong corrosion resistance, good insulation and light weight, and is the fastest developing new structural material in engineering. There are many kinds of polymer materials, which are usually divided into three categories according to their mechanical properties and service conditions in engineering: plastic, rubber and synthetic fiber.
(4) Composite materials
Composite material is a material composed of two or more different materials, and its performance is not available in other simple materials. Composite materials can be composed of various materials. It is superior to pure metals, ceramics and polymers in strength, rigidity and corrosion resistance. It is a special engineering material with broad development prospects.