Technical requirements for pistons

1. Sufficient strength, rigidity, small mass and light weight to ensure minimum inertia force.
2. Good thermal conductivity, high temperature, high pressure and corrosion resistance, sufficient heat dissipation capacity and small heating area.
3. There should be a small friction coefficient between the piston and the piston wall.
4. When the temperature changes, the size and shape should change little, and the minimum gap should be maintained between the cylinder wall.
5. Small thermal expansion coefficient, small specific gravity, good anti-friction and thermal strength.