Guo Yi, Wang Yongfei, Zhao Shengdun
School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel). 2020 Nov 21;13(22):5278. doi: 10.3390/ma13225278.
Scroll compressors are popularly applied in air-conditioning systems. The conventional fabrication process causes gas and shrinkage porosity in the scroll. In this paper, the electromagnetic stirring (EMS)-based semisolid multicavity squeeze casting (SMSC) process is proposed for effectively manufacturing wrought aluminum alloy scrolls. Insulation temperature, squeeze pressure, and the treatment of the micromorphology and mechanical properties of the scroll were investigated experimentally. It was found that reducing the insulation temperature can decrease the grain size, increase the shape factor, and improve mechanical properties. The minimum grain size was found as 111 ± 3 μm at the insulation temperature of 595 °C. The maximum tensile strength, yield strength, and hardness were observed as 386 ± 8 MPa, 228 ± 5 MPa, and 117 ± 5 HV, respectively, at the squeeze pressure of 100 MPa. The tensile strength and hardness of the scroll could be improved, and the elongation was reduced by the T6 heat treatment. The optimal process parameters are recommended at an insulation temperature in the range of 595-600 °C and a squeeze pressure of 100 MPa. Under the optimal process parameters, scroll casting was completely filled, and there was no obvious shrinkage defect observed inside. Its microstructure is composed of fine and spherical grains.
涡旋压缩机广泛应用于空调系统中。传统制造工艺会在涡旋件中产生气孔和缩松。本文提出基于电磁搅拌（EMS）的半固态多腔挤压铸造（SMSC）工艺来有效制造变形铝合金涡旋件。对保温温度、挤压压力以及涡旋件的微观形貌和力学性能进行了实验研究。结果发现，降低保温温度可减小晶粒尺寸、增加形状因子并改善力学性能。在595℃保温温度下，最小晶粒尺寸为111±3μm。在100MPa挤压压力下，最大抗拉强度、屈服强度和硬度分别为386±8MPa、228±5MPa和117±5HV。经T6热处理后，涡旋件的抗拉强度和硬度提高，伸长率降低。推荐的最佳工艺参数为保温温度在595 - 600℃范围内，挤压压力为100MPa。在最佳工艺参数下，涡旋铸件完全充满，内部未观察到明显的收缩缺陷。其微观组织由细小的球形晶粒组成。
