Ca和Nd复合合金化Mg-6Al合金显微组织和力学性能的研究

Study on Microstructure and Mechanical Properties of Mg-6Al Alloyed by Ca and Nd

以Mg-6Al-XCa-XNd合金为研究对象,采用金相组织观察、SEM、室温和高温拉伸实验以及断口组织观察等分析测试手段,研究了Ca和Nd元素含量对Mg-6Al-XCa-XNd合金微观组织和力学性能的影响规律。结果表明,随着Ca和Nd元素含量增加,Mg-6Al-XCa-XNd合金晶粒尺寸减小,Mg-6Al-3Ca-3Nd和Mg-6Al-4Ca-4Nd合金的铸态组织呈蔷薇状;Mg-6Al-XCa-XNd合金的室温拉伸强度和延伸率降低,Mg-6Al-XCa-XNd合金的175℃高温拉伸强度先增加后降低,延伸率降低。Mg-6Al-3Ca-3Nd合金的175℃高温拉伸强度值可达到141.42 MPa。室温拉伸断口表面与高温拉伸断口表面相比存在较多的微观裂纹。

The effect of Ca and Nd on the microstructure and properties of Mg-6Al-XCa-XNd alloy was studied by optical microscope,SEM ,tensile testing at room temperature and 175 ℃, and fracture morphology observation. The experimental re- sults show that the grain size of Mg-6Al-XCa-XNd alloy decreases with increasing of Ca and Nd. The grain morphology is rosi- ness-like in as-cast Mg-6Al-3Ca-3Nd and Mg-6Al-4Ca-4Nd alloy. The tensile strength and elongation of Mg-6Al-XCa-XNd al- loy decrease with increasing Ca and Nd at room temperature condition. The high temperature tensile strength increases firstly and then decreases with increasing of Ca and Nd, the maximum value is 141.42MPa for Mg-6Al-3Ca-3Nd alloy. The high temperature elongation of Mg-6Al-XCa-XNd alloy decrease with increasing Ca and Nd at high temperature condition. There are more cracks on fracture surfaces at room temperature condition than that at high temperature.