本文關(guān)鍵詞： TZM合金 Ni BNi2 擴(kuò)散連接 瞬時(shí)液相擴(kuò)散連接　出處：《哈爾濱工業(yè)大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：本文針對(duì)TZM(鉬鈦鋯)合金這種高溫結(jié)構(gòu)材料的連接需求,系統(tǒng)研究了TZM的固相擴(kuò)散連接和瞬時(shí)液相擴(kuò)散連接。利用光學(xué)顯微鏡、掃描電鏡及能譜分析、強(qiáng)度測(cè)試等方法,首先研究了使用Ni、Ti和Nb三種金屬作為中間層的固相擴(kuò)散焊接頭界面顯微組織和力學(xué)性能。通過(guò)研究工藝參數(shù)對(duì)接頭微觀組織和力學(xué)性能的影響,確定了最佳中間層材料及其添加方式和最佳工藝參數(shù),解明了接頭微觀組織和力學(xué)性能對(duì)應(yīng)關(guān)系。此外,研究了使用BNi2作為中間層的瞬時(shí)液相擴(kuò)散連接接頭的顯微組織和力學(xué)性能,通過(guò)研究工藝參數(shù)對(duì)接頭微觀組織和力學(xué)性能的確定了最佳工藝參數(shù),并且對(duì)其機(jī)理進(jìn)行了初步探究。采用Ni、Ti和Nb作為中間層在T=1100℃,P=5MPa,t=30min的焊接工藝下對(duì)TZM合金進(jìn)行擴(kuò)散連接,發(fā)現(xiàn)使用Nb作為中間層時(shí)不能對(duì)母材進(jìn)行有效地連接;使用Ni作為中間層時(shí),接頭結(jié)合良好,存在明顯的擴(kuò)散層,無(wú)新相生成,接頭的拉剪強(qiáng)度可以達(dá)到294MPa,接頭的強(qiáng)度主要取決于中間層Ni的剩余量;使用Ti作為中間層時(shí),擴(kuò)散層不明顯,但是有β相的生成,接頭的拉剪強(qiáng)度可以達(dá)到224.8MPa,接頭的強(qiáng)度主要取決于β相的含量。確定了Ni為最佳的中間層材料。同時(shí)研究了不同的中間層添加方式對(duì)接頭組織性能的影響,發(fā)現(xiàn)鍍鎳的接頭性能明顯優(yōu)于使用Ni箔,在鍍Ni 5min時(shí),接頭拉剪強(qiáng)度可以達(dá)到347.6MPa。采用50um Ni箔作為中間層對(duì)TZM進(jìn)行擴(kuò)散連接,發(fā)現(xiàn)隨著焊接參數(shù)的增大,接頭的組織和性能會(huì)趨于良好,但是溫度過(guò)高或壓力過(guò)大時(shí),工件的變形量過(guò)大。最終確定最佳焊接參數(shù)為T(mén)=1100℃,P=5MPa,t=30min。采用BNi2作為中間層對(duì)TZM進(jìn)行瞬時(shí)液相擴(kuò)散連接,對(duì)其典型接頭元素分布分析發(fā)現(xiàn)Ni元素的分布集中在等溫凝固區(qū)而且越靠近中心處Ni分布越密集,而Mo元素在越靠近中心處分布越稀疏,Fe和Cr元素分布與Ni相似,而Si元素則是在沉淀區(qū)中有明顯的集中分布。最佳焊接參數(shù)為T(mén)=1200℃,t=30min,此時(shí)接頭結(jié)合良好,接頭拉剪強(qiáng)度可以達(dá)到301.2MPa。通過(guò)對(duì)瞬時(shí)液相擴(kuò)散連接機(jī)理研究發(fā)現(xiàn)在1200℃和30min的焊接參數(shù)下等溫凝固的時(shí)間大約為15min,而成分均勻化則是整個(gè)焊接過(guò)程中時(shí)間最長(zhǎng)的階段。
[Abstract]:In this paper, the solid diffusion bonding and transient liquid phase diffusion bonding of TZM (molybdenum titanium-zirconium) alloy, a high temperature structural material, has been studied systematically. The methods of optical microscope, scanning electron microscope and energy dispersive spectrum analysis, strength measurement and so on have been used. The microstructure and mechanical properties of the interface of solids diffusion welded joints using Niti and NB as interlayers were studied. The effects of process parameters on the microstructure and mechanical properties of the joints were studied. The optimum interlayer material, its addition mode and optimum process parameters are determined, and the relationship between the microstructure and mechanical properties of the joints is obtained. The microstructure and mechanical properties of transient liquid phase diffusion bonding joints with BNi2 as the interlayer were studied. The optimum process parameters were determined by studying the process parameters. The diffusion bonding of TZM alloy was carried out by using Niti Ti and NB as interlayer under the welding process of 30 minutes at 1 100 鈩，

本文編號(hào)：1525072