(清華大學(xué)機(jī)械工程系，北京 100084
中國科學(xué)院金屬研究所，沈陽 110015)
摘 要: 分析了Si3N4/40Cr鋼釬焊接頭緩沖層機(jī)制。利用壓力釬焊促進(jìn)緩沖層產(chǎn)生塑性變形，降低了接頭的殘余應(yīng)力，提高了接頭強(qiáng)度。軟性緩沖層Cu和Nb易于產(chǎn)生較大的塑性變形，接頭強(qiáng)度有明顯提高；硬性緩沖層Ta不易產(chǎn)生塑性變形，接頭強(qiáng)度無明顯提高 。緩沖層塑性變形愈大，接頭強(qiáng)度愈高。使用Cu作緩沖層材料，當(dāng)外加壓力為27 MPa時(shí)，接頭拉伸強(qiáng)度可達(dá)62.3MPa。EPMA結(jié)果表明，在加壓和無壓狀態(tài)下 ，接頭中各元素在垂直界面方向上的總體分布不發(fā)生變化。加壓可以減小接頭釬縫寬度，控制接頭間隙。壓力釬焊也有助于其它異種材料的連接。
關(guān)鍵字: Si3N4/40Cr鋼 壓力釬焊 殘余應(yīng)力 緩沖層
（Department of Mechanical Engineering，Tsinghua University, Beijing 100084, P. R. China
Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110015, P. R. China）
Abstract:The buffer mechanism in the Si3N4/40Cr steel joint was analyzed. Pressure brazing was employed to increase the joint strength by the plastic deformation of the buffer layer and the decrease of the residual stresses. The soft buffers such as Cu and Nb are apt to be deformed and result in increase of the joint strength, the hard buffers such as Ta are reversed. The larger the plastic deformation of the buffer layer, the higher the joint strength. As a result, the joint tensile strength is 62.3MPa with Cu as a buffer and 27MPa exterior pressure. It was drawn up from EPMA that the element distributions vertically along interface do not change whether with or without pressure and that the joining gaps decrease with pressure. Other dissimilar materials bonding can benefit by pressure brazing.
Key words: Si3N4/40Cr steel pressure brazing residual stress buffer
