CAJ | 학술논문

用热压法制备Ti/Al扩散偶,并在525,550,575,600℃进行热处理.结果表明:当Al未完全消耗时,TiAl3是Ti/Al界面处唯一的产物,TiAl3向Al箔一侧长大,Ti箔中没有检测到Al原子的存在.从固溶体的溶解度极限,Al、Ti和TiAl3的晶格失配度,以及新相形成所增加的界面能3个方面解释TiAl3的首先生成.Ti在Al中的溶解度极限很小,Al(Ti)固溶体很容易生成,以及Al、Ti和TiAl3的密排面错配度很小,促使TiAl3优先形核.在所有Ti-Al化合物中,形成TiAl3所增加的界面能最少,有利于TiAl3优先形核长大.由于动力学的不稳定性,其他Ti-Al化合物的生成与长大受到抑制.
용열압법제비Ti/Al확산우,병재525,550,575,600℃진행열처리.결과표명:당Al미완전소모시,TiAl3시Ti/Al계면처유일적산물,TiAl3향Al박일측장대,Ti박중몰유검측도Al원자적존재.종고용체적용해도겁한,Al、Ti화TiAl3적정격실배도,이급신상형성소증가적계면능3개방면해석TiAl3적수선생성.Ti재Al중적용해도겁한흔소,Al(Ti)고용체흔용역생성,이급Al、Ti화TiAl3적밀배면착배도흔소,촉사TiAl3우선형핵.재소유Ti-Al화합물중,형성TiAl3소증가적계면능최소,유리우TiAl3우선형핵장대.유우동역학적불은정성,기타Ti-Al화합물적생성여장대수도억제.
Ti/Al diffusion couples fabricated by hot pressing were annealed at 525, 550, 575 and 600 ℃. TiAl3 was the only observed phase at the Ti/Al interface when the unreacted Al foils remained. TiAl3 grew towards Al foil side. Few Al atoms were detected in Ti foils. The first formation of TiAl3 is explained on the basis of solubility limits of terminal solid solution, lattice mismatch among Al, Ti and TiAl3, and the increasing interfacial energy caused by newly formed interface. The first saturation of Al(Ti)solid solution due to the little solubility of Ti in Al, and the slight misfit among the close-packed planes of Al, Ti and TiAl3, advance the nucleation of TiAl3. TiAl3, rather than other compounds, has the lowest increasing interfacial energy, indicating its preferential formation. The formation of other titanium aluminides is suppressed due to their growth which is kinetically unstable.