Mechanism for friction reduction of aluminum alloy at high-pressure and ultra-low temperature

Temperature and pressure have a significant impact on friction in aluminum alloy ultra-low temperature forming. In this paper, cryogenic strip drawing test (CSDT), morphologies analysis and microstructure characterization were used for friction mechanism investigation of aluminum alloy under different temperatures and pressures. The findings indicated that the coefficient of friction (COF) first increased and then decreased as pressure increased. From 2 to 10 MPa, the lowest COF was observed at −190 °C. The formation of fine deformation microstructure enhanced surface material plasticity and resistance to deformation leading to reduced adhesive friction or plowing friction, resulting in low COF at high-pressure and ultra-low temperature. Furthermore, higher temperatures and pressures increased the adhesion, which was detrimental to prolonging the service life of die.