【作者】 徐洪辉； 杜勇； 陈海林； 贺跃辉； 潘竹；

【Author】 Honghui Xu, Yong Du, Chen Hailin, He Yuehui, Pan Zhu State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China

【机构】 中南大学粉末冶金国家重点实验室；

【摘要】 采用三元扩散偶结合11个关键合金测定了Nb-Ti—Si系1000℃等温截面。其中,关键合金的成分是依据扩散偶实验结果选定的。扩散偶和合金样品借助光学显微、扫描电镜和电子探针显微分析技术进行分析。在该等温截面,没有发现三元化合物,存在7个三相平衡[1:TiSi2+NbSi2+Si,2: TiSi2+TiSi+Ti5Si4,3:TiSi2+NbSi2+Ti5Si4,4:Ti5Si4+NbSi2+Nb5Si3,5:Ti5Si4+Ti5Si3+Nb5Si3,6: Ti5Si3+Nb5Si3+Ti3Si及7:Nb5Si3+Ti3Si+(Nb,Ti)]。Nb在Ti3Si,Ti5Si4和TiSi2中的固溶度分别高达60, 41和17．6 at．％Nb。Ti在Nb5Si3和NbSi2中的固溶度分别高达31和13 at．％Ti。更多还原

【Abstract】 The isothermal section at 1000 ℃ of the Nb-Ti-Si system was constructed using a high-efficiency diffusion triple approach, supplemented with 11 alloys, the composition of which were selected in terms of the experimental results from the diffusion triple. Both the diffusion triple specimens and the alloys were examined by means of optical microscopy, scanning electron microscopy, and electron probe microanalysis. No ternary compound was found at this isothermal section. Seven three-phase equilibria were observed [1: TiSi2+NbSi2+Si, 2: TiSi2+TiSi+Ti5Si4, 3: TiSi2+NbSi2+Ti5Si4, 4: Ti5Si4+NbSi2+Nb5Si3, 5: Ti5Si4+Ti5Si3+Nb5Si3, 6: Ti5Si3+Nb5Si3+ Ti3Si and 7: Nb5Si3+Ti3Si+(Nb,Ti)]. The solubilities of Nb in Ti3Si, Ti5Si4 and TiSi2 were determined to be up to about 60, 41 and 17.6 at.% Nb, respectively. In the case of Ti in Nb5Si3 and NbSi2, the values of about 31 and 13 at.%Ti were found, respectively.更多还原