(哈爾濱工業(yè)大學(xué) 現(xiàn)代焊接生產(chǎn)技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，
哈爾濱 150001)
摘 要: 在1173~1373K、 0.3~5.4ks的接合條件下對(duì)TiAl金屬間化合物與40Cr鋼進(jìn)行了真空擴(kuò)散連接。 采用掃描電鏡(SEM)、 電子探針微區(qū)成分分析(EPMA)、 X射線(xiàn)衍射分析(XRD)等方法確定了反應(yīng)相的種類(lèi)和界面結(jié)構(gòu)。 研究結(jié)果表明，在1373K的接合溫度下， TiAl/40Cr接頭生成了TiC, Ti3Al, FeAl和FeAl24種反應(yīng)相，形成了3個(gè)反應(yīng)層， 界面結(jié)構(gòu)為T(mén)iAl/Ti3Al+FeAl+FeAl2/TiC/脫碳層/40Cr鋼。 界面總反應(yīng)層的厚度隨接合溫度和接合時(shí)間按拋物線(xiàn)方程成長(zhǎng)， 成長(zhǎng)的活化能Q為211.9kJ/mol, 成長(zhǎng)常數(shù)k0為4.6×10－5m2/s。 當(dāng)脆性反應(yīng)層厚度為3μm時(shí)， TiAl/40Cr鋼接頭的室溫拉伸強(qiáng)度達(dá)到183MPa的最大值。
關(guān)鍵字: TiAl； 擴(kuò)散連接； 界面結(jié)構(gòu)； 反應(yīng)機(jī)理；接頭強(qiáng)度
（National Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:TiAl intermetallic compound was joined to 40Cr steel by diffusion bonding at the temperature range of 1173~1373K for 0.3~5.4ks in vacuum. Reaction phases and interface structures were investigated by SEM, EPMA analysis and XRD diffraction method. At the bonding temperature of 1373K, four phases of TiC, Ti3Al, FeAl and FeAl2 were established and three layers were formed in the TiAl/40Cr joint, the interface structures were observed as TiAl/ Ti3Al+FeAl+FeAl2/TiC/decarbonized layer/40Cr steel. The total reaction layer grows with the joining time following the parabolic law, the activation energy Q and rate constants k0 for the growth are 211.9kJ/mol and 4.6×10－5m2/s respectively. At the 0.3μm reaction layer thickness of TiC+Ti3Al+FeAl+FeAl2, the maximum strength of the TiAl/40Cr joint is up to 183MPa at room temperature.
Key words: TiAl; diffusion bonding; interface structure; reaction mechanism; joining strength
