Selection and Process of Gear Transmission Materials

The material selection of general mechanical transmission systems is a broad concept. Here, I will mainly talk about the situation of gear transmission in iron-based friction pairs, which is the selection of gear materials.

Gears can be made of various materials, including steel, copper, cast iron, aluminum, plastic, and so on. Among them, steel is the most common and ideal material, with high cost-effectiveness, good wear resistance, and good strength. Through heat treatment, good mechanical properties can also be obtained.

The material and heat treatment process of gear processing will have an impact on the bearing capacity, size, and weight of gears. Before the 1950s, carbon steel was used for gears, alloy steel was used in the 1960s, and surface hardening steel was used in the 1970s. According to the hardness of the tooth surface, gears can be divided into soft tooth surface and hard tooth surface.

The commonly used materials for manufacturing gears include forged steel and cast steel, followed by cast iron. In special cases, non-ferrous and non-metallic materials can also be used. Steel: Steel with a carbon content of 1% -6% is commonly used because it has the best performance (mechanical properties can be improved through heat treatment). Forged steel: Just now, after forging, the performance has improved, and the most commonly used is 45 # steel.

The materials used in designing and manufacturing gears will depend on the type of gear being manufactured and the operating conditions. The materials of gears are copper alloy, iron alloy, tool steel alloy, and aluminum alloy, etc.

Cast steel is commonly used for larger gears. Cast iron and gray iron have brittle properties, poor impact and wear resistance, but have better resistance to adhesion and pitting corrosion. Gray iron gears are commonly used in scenarios where work is smooth, speed is low, and power is not high.