The solution treatment of aluminum alloy, copper alloy, titanium alloy, tempered glass and other materials or heat treatment with rapid cooling process is called quenching.

Tempering is also called fire matching. A metal heat treatment process. Reheat the quenched workpiece to an appropriate temperature below the lower critical temperature, keep the temperature for a period of time, and then cool it in air, water, oil and other media for metal heat treatment. Or heating the quenched alloy workpiece to a proper temperature, keeping the temperature for a certain time, and then slowly or rapidly cooling. It is generally used to reduce or eliminate the internal stress in hardened steel parts, or reduce their hardness and strength, so as to improve their ductility or toughness. According to different requirements, low temperature tempering, medium temperature tempering or high temperature tempering can be adopted. Usually, with the increase of tempering temperature, hardness and strength decrease, and ductility or toughness gradually increase.