ZL104铝合金连杆半固态挤压铸造工艺实验研究

Experimental Study on Semi-solid Squeeze Casting Process of ZL104 Aluminum Alloy Connecting Rod

摘要:

研究了传统液态挤压铸造与半固态挤压铸造成形ZL104铝合金连杆的充填状态、微观组织及力学性能。结果表明：传统液态挤压铸造成形连杆充填饱满,但其抗拉强度及伸长率低于半固态挤压铸造成形连杆。对于半固态挤压铸造成形,浇注温度高于565℃时,铸件充填性能良好；平均晶粒尺寸及形状因子随浇注温度的升高而逐渐升高；连杆抗拉强度及伸长率先增加后减小。挤压压力高于25MPa时,铸件均充填饱满; 挤压压力升高,平均晶粒尺寸不断减小且形状因子不断增大,连杆机械性能不断提高。模具预热温度升高,平均晶粒尺寸和形状因子不断增大,连杆机械性能逐渐提高。但当模具预热温度超过300℃时,平均晶粒尺寸进一步增大而其形状因子减小,导致连杆的机械性能下降。

Abstract:

The filling states, microstructures and mechanical properties of ZL104 aluminum alloy connecting rod prepared by traditional liquid squeeze casting (LSC) and semi-solid squeeze casting (SSSC) processes were investigated. Results show that, During the LSC process, the connecting rod is fully filled and its microstructure is a typical dendritic structure. However, its tensile strength and elongation are lower than the connecting rod prepared by SSSC process. During the SSSC process, when the pouring temperature is higher than 565 ℃, the connecting rod is fully filled; the average grain size and shape factor are improved with the increase in the pouring temperature; the tensile strength and elongation is increased first and then decreased. When the squeezing pressure is higher than 25 MPa, the connecting rod is filled full; with increasing the squeezing pressure, the average grain size is gradually decreased, the shape factor is gradually increased, and the mechanical properties are gradually improved. Additionally, with the increase in the mould preheating temperature, the average grain size and shape factor are gradually increased, and mechanical properties are gradually improved. However, when the mould preheating temperature is higher than 300 ℃, the average grain size is further increase and the shape factor is decreased, resulting in the decrease of the mechanical properties of the connecting rod.