氧化铝陶瓷钎焊工艺与接头强度的研究

STUDY ON BRAZING PROCESS AND JOINT STRENGTH OF ALUMINAC CERAMICS

用Ａｇ＿５７Ｃｕ＿３８Ｔｉ＿５钎料研究了氧化铝陶瓷真空钎焊，探讨了钎焊温度（８００～１０５０℃）、压力（０～０．３ＭＰａ）和时间（０～６０ｍｉｎ）对接头强度的影响规律，分析了界面形貌与接头强度之间的关系。结果表明：陶瓷与钎料之间存在一明显反应过渡层，反应层强度和反应层与用瓷间的连结强度是控制接头强度的主要因素。当钎焊温度过低或过高、钎焊时间过短或过长时，由于界面反应不充分或脆性反应产物增加以及界面部分开裂等原因，接头强度均较低。适当的钎焊压力可使界面接触面积增加，对接头强度有利。在８５０℃，０．０１ＭＰａ和钎焊３０ｍｉｎ工艺条件下可获得最大接头强度。

The brazing of alumina ceramics in vacuum was performed using Ag_57Cu_38Ti_5 as filler metal.The effects of welding conditions such as welding temperature(from 800℃ to 1050℃),holding time(0 to60min)and welding pressure(0 to 0. 3MPa) on the joint strength were investigated.The relation of interfacialmorphology and joint strength was also analysed.It is shown that an interfacial reaction layer is observed be-tween the ceramics and the filler metal, and the joint strength depends mainly on the reaction layer strengthRecived:December 14,1993.Correspondent :Hao Hongqi,Department of Materials Science and Engineering,Xi’an Jiaotong University,Xi’an 710049.and interfacial bonding strength between reaction layer and ceramics. When welding temperature is too lowand holding time is too short,interfacial reaction is insufficient so that both the strength of reaction layer andinterface bonding become low.When temperature is too high and holding time too long, the joint strength isstill low because the amount of brittle reaction products increases and cracks occur on the interface.A suitablewelding pressure is beneficial to welding strength because the true contact area between ceramics and fillermetal is expanded.The maximum shear strength is obtained at 850℃ for 30min under a pressure of0.01MPa.