作　　者： (唐昌平）; (李国栋）; (刘文辉）; (陈宇强）; (刘筱）; (李方伟）;

机构地区： 湖南科技大学材料科学与工程学院,湘潭411201 高温耐磨材料及制备技术湖南省国防科技重点实验室,湘潭411201

出　　处： 《材料导报》 2017年第16期103-106,共4页

摘　　要： 采用金相观察、硬度测试、扫描电镜观察、透射电镜观察及室温压缩等手段,研究了时效析出相对Mg-5.5Gd-3.0Y-1.0Nd-1.0Zr合金挤压棒材室温压缩性能的影响。结果表明:该合金具有优异的抗压性能,经225℃/12h时效处理后,合金的抗压强度可达490 MPa,屈服强度可达325 MPa,总压缩应变为8.9%,优异的抗压强度主要归因于合金中与基体呈半共格关系的析出相β′;随着时效程度的进一步增加,合金进入过时效状态,在300℃下时效8h后,合金中析出尺寸达微米级的平衡相β,并在晶界处形成宽度约2 μm的无沉淀析出带,使合金的强化效果减弱;断口分析表明,不同时效状态合金均以解理断裂为主,并在解理面之间以少量韧窝进行连接。 Effects of precipitates on compression behavior of Mg-5.5Gd-3.0Y-1.0Nd-1.0Zr at ambient temperature were investigated by optical microscopy（OM）,hardness testing,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）and ambient temperature compression test.The results indicated that the compression property of the alloy was very excellent.After 225 ℃ /12 htreated,the compressive strength of the alloy could achieve 490 MPa,the yield strength could achieve 325 MPa,and the total compressive strain could reach 8.9% .The excellent compressive strength was attributed to theβ′precipitate,which was semi-coherent with the magnesium matrix.The alloy became overage as the aging time prolonged.The micrometer scaled equilibriumβphase precipitated from the matrix after aged at 300℃ for 8 h.The precipitate free zone with width of about 2 μm was formed at the grain boundary,which weakened the strengthening effect.The fracture analysis indicated that cleavage fracture was the main fracture mode,and the cleavage planes were connected by a small amount of dimples.

关 键 词： 合金 时效 析出相 室温压缩 断口分析