【摘要】 研究脉冲电流对不同温度下的钛基复合材料钨极氩弧焊接头的显微组织、硬度和拉伸性能的影响。采用或不采用脉冲电流,均能得到全熔透的对接焊接头。运用光学显微技术、硬度测试和扫描电镜观察对焊接接头的冶金特性进行分析,研究不同温度下与显微组织密切相关的焊接接头的拉伸性能。结果表明,脉冲电流导致焊缝区的显微组织和TiB晶须尺寸显著细化,并改变TiB增强体的重新分布状态,从而使得脉冲焊接接头具有较高的硬度、拉伸强度和伸长率。更多还原

【Abstract】 The effects of current pulsing on the microstructure, hardness and tensile properties at different temperatures of gas tungsten arc(GTA) weldments of titanium matrix composites were studied. Full-penetration butt joints were made with or without current pulsing. Optical microscopy, hardness test and scanning electron microscopy were employed to evaluate the metallurgical characteristics of welded joints. Tensile properties of weldments at different temperatures were studied and correlated with the microstructure. The results exhibit that current pulsing leads to the refinement of the weld microstructure and TiB whisker and the redistribution of reinforcements resulting in higher hardness, tensile strength and ductility of weldments in the as-welded condition.更多还原