航天器件电铸镍焊接裂纹的研究

本工作以某些重要航天器件制造中遇到的实际问题为背景,对电铸镍与1Cr18Ni9Ti焊接接头电铸镍一侧近缝区的裂纹进行了深入研究。采用可变拘束裂纹试验法确定了电铸镍产生裂纹的最小临界应变量。采用Gleeble—1500试验机系统地研究了加热过程及以不同速度冷却过程中电铸镍的热塑性。运用扫描电镜、透射电镜及其能谱分析仪等于段对裂纹表面、热塑性试样断口以及薄膜试样的晶界区进行了系统分析。研究确定,电铸镍近缝区裂纹本质上是一种起裂于熔合区的特殊液化裂纹。研完了裂纹的形成温度与主要影响因素,并提出了控制措施。

The Investigation on Welding Cracks of Electroformed Nikel of Aero-space Components

On the basis of analysis of some practical problems occurred during manufacturing of some aero-space components, the cracks in welding of electroformed Nikel with 1 Crl8Ni9Ti steel which appeared near the side of the electroformed Nikel are investigated in this paper. The minimum critical strain that existed during the time when weld cracks formed in electroformed Nikel is determined with testing method of variable restriction cracks. The hot-ductilities of the electroformed Nikel in heating process and cooling are studied systematically with Gleeble-1500 tester. The crack surface fracture of hot-ductility sample and the region of crystal boundary of thin film sample are fully analyzed with scanning electron microscope, transmission electron microscope and its spectrometer, etc. It is determined that the cracks of electroformed Nikel near weld bond are essentially a special liquation crack which originates from weld bond. The forming temperature of cracks and main affecting factors are discussed, and the control measures are presented.