固相再生Mg-Nd-Zn-Zr镁合金的时效强化  

Aging strengthening of Mg-Nd-Zn-Zr magnesium alloy prepared by solid recycling process

作　　者：文丽华[1] 吉泽升[2] 许红雨[2] 王宝芹[1] 宁慧燕[1] 翁江翔[1] 胡茂良[2] 

机构地区：[1]黑龙江工程学院机电工程学院,哈尔滨150050 [2]哈尔滨理工大学材料科学与工程学院,哈尔滨150040

出　　处：《中国有色金属学报》2016年第7期1408-1413,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51404082);黑龙江省教育厅科学技术研究面上项目(12541660)~~

摘　　要：研究固相再生Mg-2.4Nd-0.4Zn-0.4Zr镁合金等温时效过程的析出强化行为。利用TEM、SEM对时效析出相的形态和断裂行为进行分析。结果表明:200℃、16 h时效时合金力学性能达到峰值,抗拉强度为294.5 MPa,伸长率为13.5%。此时,晶内弥散析出杆状β′亚稳相和片状β稳定相,使合金获得较高强度。在200℃、60 h过时效作用下,β′亚稳相原位长大成β稳定相,合金的强度下降,塑性上升;欠时效时合金以穿晶剪切断裂为主,峰时效时合金以穿晶韧窝和沿晶断裂为主,过时效时粗大的第二相对断裂过程有着较大的影响。The precipitation strengthening behavior of Mg-2.4Nd-0.4Zn-0.4Zr magnesium alloy prepared by solid recycling process during aging was investigated. The microstructure of the precipitates and fracture behavior were examined by TEM and SEM. The results show that the peak ultimate tensile strength, elongation of the alloy is 294.5 MPa and 13.5%, respectively, when aged at 200 ℃ for 16 h. The alloy exhibits good strength due to precipitation of the rod-like β′ metastable phase and the flaky β stable phase. The β′ phase transforms into the β stable phase in-situ when aged at 200 ℃ for 60 h. This induces decline of the strength and increasing of the plasticity. Fracture mode is mainly transgranular tearing fracture at the early stage of aging. Fracture mode is a mix mechanism with transgranular dimple fracture and intergranular fracture in the peak-ageing. Bigger second phases have largely effected on fracture in the further-ageing.

关 键 词：Mg-Nd-Zn-Zr镁合金 时效强化 组织 力学性能 断裂行为 

分 类 号：TG146.2[一般工业技术—材料科学与工程]