摘要
The microstructural characteristics, mechanical properties and creep resistance of Mg-（8%-12%） Zn-（2%-6%） A1 alloys were investigated to get a better overall understanding of these series alloys. The results indicate that the microstructure of the alloys ZA82, ZA102 and ZA122 with the mass ratio of Zn to A1 of 4-6 is mainly composed of a-Mg matrix and two different morphologies of precipitates （block τ-Mg32（Al, Zn）49 and dense lamellar ε-Mg51Zn20）, the alloys ZA84, ZA104 and ZA124 with the mass ratio of 2-3 contain α-Mg matrix and only block r phases, and the alloys ZA86, ZA106 and ZA126 with the mass ratio of 1-2 consist of a-Mg matrix, block r precipitates, lamellar Ф-Al2Mg5Zn2 eutectics and flocculent β-Mg17Al12 compounds. The alloys studied with the mass ratio of Zn to A1 of 2-3 exhibit high creep resistance, and the alloy ZA124 with the continuous network of r precipitating along grain boundaries shows the highest creep resistance.
研究了Mg-(8%～12%)Zn-(2%～6%)Al合金的微观组织特征、力学性能以及高温蠕变性能。结果表明,Zn/Al质量比在4～6的ZA82、ZA102和ZA122合金的显微组织主要由α-Mg、致密层片状ε-Mg_(51)Zn_(20)相和块状τ-Mg_(32)(Al,Zn)_(49)相组成。中等质量比(2～3)的ZA84、ZA124合金显微组织中的中间相主要为沿晶界呈半连续或连续分布的块状τ相。Zn/Al质量比较小(1～2)的ZA86、ZA126合金显微组织中的中间相组织主要由块状τ相、层片状φ-Al_2Mg_5Zn_2相和一些依附于这些中间相附近呈团絮状的β-Mg_(17)Al_(12)相组成。Zn/Al质量比值在2～3时,合金的抗蠕变性能较好,其中具有连续网状分布的块状τ相组织的ZA124合金显示出最好的蠕变抗力。
基金
Project(10KJB430012) supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China
Project (BK2011063) supported by the Nantong Science and Technology Commission of China
