压铸工艺参数和冷却速度对B390铝合金表面贫硅区的影响

Influence of Die-casting Process Parameters and Cooling Rates on the Surface Silicon-depleted Zone of B390 Aluminum Alloy

以B390铝合金为研究对象,采用高压铸造法制备压铸试棒。通过凝固过程模拟和金相试验表征与统计,分析浇注温度、压射压力、压射速度等压铸工艺参数对压铸件表面贫硅区的影响。采用AnyCasting软件模拟压铸件的充型和凝固过程,确定3种典型冷却速度的位置并取样,结合压铸工艺参数研究和试验分析,发现:压铸件表面贫硅区的厚度随着浇注温度的升高而减小,随着压射速度和冷却速度的增加而增加,压射压力对其影响较小;在压射压力为85MPa,浇注温度为740℃和压射速度为1 m/s时,压铸件表面贫硅区的厚度最小,有利于提高其耐磨性能。

Test bars of the B390 aluminum alloy were made through high pressure die casting(HPDC).The influence of HPDC processing parameters(pouring temperature,injection pressure,and injection speed)on the surface silicon-depleted zone(SDZ)of die-cast part was investigated through solidification process simulation,optical micrograph characterization and statistical analysis on test bars.Three typical locations with different cooling rates were identified for sampling by simulation of the filling and solidification process using AnyCasting software.Combining the HPDC parameters study and experimental analysis,it was found that the thickness of SDZ decreased with the increase of pouring temperature,increased with the increase of injection speed and cooling rate,and was less affected by the variation of injection pressure.The minimal thickness of SDZ was obtained at the pouring temperature of 740℃,injection pressure of 85 MPa and injection speed of 1 m/s,which was beneficial to the improvement in wear resistance of die-cast part.