摘要
研究在旋转速度分别为1600、1800、1900 r/min的工艺参数下对LZ91镁锂合金进行搅拌摩擦加工的改性试验。采用光学显微镜、万能试验机和显微硬度测试仪来分析旋转速度对试样显微组织和力学性能的影响。结果表明:当加工速度为60 mm/min,在旋转速度1600~1900 r/min增加的情况下,焊核区和前进侧热机影响区α-Mg相和β-Li相平均晶粒尺寸均变大,而后退侧热机影响区α-Mg相和β-Li相平均晶粒尺寸却先减小后增加。经搅拌摩擦加工改性后,LZ91镁锂合金抗拉强度、伸率长和焊核区的显微硬度均有显著提升,且呈现为先变大后减小的趋势。在旋转速度增加至1800 min时,抗拉强度达到最大值252.0 MPa,抗拉强度相比搅拌摩擦加工改性前增加了36%。
The modification test of LZ91 magnesium lithium alloy was carried out under the process parameters of 1600r/min, 1800 r/min and 1900 r/min, respectively. Optical microscope, universal testing machine and microhardness tester were used to analyze the effect of rotation speed on the microstructure and mechanical properties of the samples. The results show that when the advancing speed is 60 mm/min and the rotation speed increases from 1600 r/min to 1900 r/min, the grain size ofα-Mg phase and β-Li phase in the nugget area and the thermo-mechanically affected zone on the advancing side increases,however, the grain size of α-Mg phase and β-Li phase in the thermo-mechanically affected zone on the retreating side first decreases and then increases. After friction stir processing modification, the tensile strength, elongation and microhardness of nugget zone of LZ91 magnesium lithium alloy significantly improves, which show a trend of first increasing and then decreasing. When the rotation speed increases to 1800 r/min, the tensile strength reaches the maximum value of 252.0 MPa,and the tensile strength increases by 36% compared with that before friction stir processing modification.
作者
刘刚
张玺
武冰冰
解芳
马振铎
LIU Gang;ZHANG Xi;WU Bingbing;XIE Fang;MA Zhenduo(School of Intelligent Manufacturing,Nanyang Institute of Technology,Nanyang 473000;College of Materials Science and Engineering of Chongqing University,Chongqing 400044,China)
出处
《热加工工艺》
北大核心
2022年第16期18-21,共4页
Hot Working Technology
基金
国家自然科学基金项目(51701026)
湖北省自然科学基金项目(2019CFC909)
河南省高等学校重点科研项目(20A430020)
南阳理工学院博士科研启动项目(510109)。
关键词
LZ91镁锂合金
搅拌摩擦加工
旋转速度
晶粒尺寸
性能
LZ91 magnesium lithium alloy
friction stir processing
rotation speed
grain size
properties
