A comparative study on combustion synthesis of Ti–Si compounds
A comparative study on combustion synthesis of Ti–Si compounds
复制标题
DOI：
10.1016/j.jallcom.2006.10.074
复制
发表时间：
2006-09
影响因子：
6.2
通讯作者：
C. Yeh;W. Chen
中科院分区：
文献类型：
--
作者：
C. Yeh;W. Chen
采用自蔓延高温合成（SHS）技术，对Ti-Si系中特定钛硅化合物（包括Ti 3Si、Ti 5Si 3、Ti 5Si 4、TiSi和TiSi 2）的制备进行了对比研究。研究了初始化学计量比对燃烧特性和产物组成的影响。实验证据表明，在本研究中采用的所有样品中，一个独特的燃烧前横穿整个反应物紧凑的自我维持的方式。然而，作为共晶反应的结果，由Ti：Si=3：1和1：1组成的测试样品在反应前沿的传播期间经历过度熔化。此外，火焰前锋的传播速率和燃烧温度被发现显着不同的起始化学计量的粉末压块。在Ti：Si=5：4和5：3的样品中观察到的火焰前锋速度高达50 mm/s，而Ti：Si=1：2的压坯的火焰前锋速度在2.6-3.5mm/s范围内。通过Ti：Si=5：4和5：3的粉末压块实现了1380和1460°C之间的反应前沿温度。对于Ti：Si=3：1和1：1的样品，它们的火焰前缘温度相当，约为1330°C。与其缓慢的反应前沿一致，Ti+2Si样品具有接近1150°C的最低燃烧温度。XRD分析证实从具有Ti：Si=5：3的反应物完全转化为单相硅化物Ti 5Si 3。Ti：Si=5：4和1：1的粉末压坯在其最终产物中产生两种硅化物相，Ti 5Si 4和TiSi。尽管形成了少量的TiSi，但二硅化物TiSi 2被鉴定为从Ti+2Si样品获得的产物中的主要成分。Ti：Si=3：1的粉末压坯燃烧产物中含有Ti 5Si 3和大量未反应的Ti，表明相转化程度较差。
A comparative study on the preparation of specific titanium silicides (including Ti3Si, Ti5Si3, Ti5Si4, TiSi, and TiSi2) in the Ti–Si system was experimentally conducted by self-propagating high-temperature synthesis (SHS) from elemental powder compacts of their corresponding stoichiometries. The effect of initial sample stoichiometry was investigated on combustion characteristics and product composition. Experimental evidence shows a distinct combustion front traversing the entire reactant compact in a self-sustaining manner for all of the samples adopted in this study. However, as a result of the eutectic reaction, test samples composed of Ti:Si=3:1 and 1:1 experienced excessive melting during the propagation of the reaction front. Moreover, the flame-front propagation rate and combustion temperature were found to vary significantly with starting stoichiometry of the powder compact. The flame-front velocity up to 50mm/s was observed in the samples of Ti:Si=5:4 and 5:3, in contrast to the values in the range of 2.6–3.5mm/s for the compact of Ti:Si=1:2. Reaction front temperatures between 1380 and 1460°C were achieved by the powder compacts with Ti:Si=5:4 and 5:3. For the samples of Ti:Si=3:1 and 1:1, their flame-front temperatures were comparable and about 1330°C. Consistent with its slow reaction front, the Ti+2Si sample had the lowest combustion temperature close to 1150°C. The XRD analysis confirms complete conversion from the reactant with Ti:Si=5:3 to a single-phase silicide Ti5Si3. Powder compacts of Ti:Si=5:4 and 1:1 yielded two silicide phases, Ti5Si4and TiSi, in their end products. In spite of formation of a minor amount of TiSi, the disilicide TiSi2was identified as the dominant composition in the product obtained from the Ti+2Si sample. Combustion products containing Ti5Si3and a large amount of unreacted Ti were synthesized from the powder compacts of Ti:Si=3:1, implying a poor degree of phase conversion.