Immersion end quenching experiment and finite element simulation of temperature field of 2195 Al-Li alloy
Through immersion-end quenching experiments and finite element simulations,we investigated the quenching temperature field,obtained cooling curves and hardness at different locations,and combined microscopic structure analysis to explore the quenching sensitivity mechanism of Al-Li alloys.The results indicate that there is a nonlinear relationship between the interfacial heat transfer coefficient of Al-Li alloy plates and the surface temperature.As the surface temperature of the sample decreases,the interfacial heat transfer coefficient initially increases and then decreases,reaching a maximum value of 28.3 kW/(m2∙℃)at around 101℃during immersion end quenching.When 2195 aluminum-lithium alloy is quenched by immersion end quenching,the quenching rate decreases with increasing distance from the immersion end.With the decrease in quenching rate,the size and area fraction of quenched phases increase,leading to a decrease in hardness.When the quenching rate decreases from 402.5℃/s to 3.9℃/s,the hardness reduction rate is 25.6%.The relationship curves were established for hardness value(H)and hardness reduction rate(ΔH)with the area fraction(A)of quenched phases.In the slow quenching process,due to the continuous precipitation of quenched phases,the subsequent precipitation and growth of the T1 phase during aging are affected,resulting in a significant decrease in the strengthening effect and a substantial reduction in alloy hardness.
Al-Li alloyend quenchingtemperature fieldfinite element methodquenching precipitated phase