基于热传导反算法,建立了液态金属与压室之间传热的二维反算数学模型,设计了压室内部测温模块并进行了针对Al-9%Si-3%Cu合金的静态无压射和常规压铸实验.基于实验中测得的压室内部不同位置的温度,求解得到了液态金属在压室中的温度场及其不同位置的界面换热系数,为预测压室预结晶提供可靠依据.结果表明,静态无压射条件与常规压铸条件下液态金属与压室界面换热情况差异很大,同时压室中间界面换热系数均随液态金属流动方向依次降低,压室壁温度也存在两端高中间低的分布.在常规压铸条件下,由于冲头运动的影响,压室末端换热系数存在双峰现象.
A 2D inverse heat transfer model between molten metal and shot sleeve was based on the nonlin- ear estimation method. Die casting experiments under both non-shot and shot conditions (via the plunger) were per- formed using an Al-9%Si-3%Cu alloy. Based on the temperature measurements from thermocouples embedded in- side the shot sleeve, the temperature distribution of molten metal and interracial heat transfer coefficient (IHTC) were successfully determined. Results show that the heat transfer behavior of non- shot condition was different from that in the shot condition, but the IHTC in the middle zone of shot sleeve decreased along the plunger moving direction. Besides, the surface temperature of shot sleeve was higher in both pouring zone and end zone while lower in the middle zone. In accordance to the movement of the plunger, the IHTC profile in the end zone exhibited double peaks.