(重庆大学 材料科学与工程学院，重庆 400044)
摘 要: 采用通管滴落法研究1758 K温度下Ti-Al系合金熔体与TiN的润湿行为，结果表明：当Al的质量分数为40%、50%、60%、70%和80%时，初始接触角分别为68°、92°、106°、140°和140°，初始接触角对合金成分依赖较大。当Al含量较高时，Al会氧化生成Al2O3膜包裹在液滴表面，影响初始接触角的测量，但平衡接触角对合金成分依赖较小，均小于20°，且随Al含量的增加略微减小。由于润湿后试样的界面上富集了大量的Ti和少量的Al而没有明显的化学反应产物存在，且通过计算可知合金中Ti的化学势明显高于基板中Ti的化学势，因此，在化学势差的作用下Ti向界面吸附，促进体系的润湿。此外，当Al含量大于60%时，在铺展的末期Al会显著挥发，但其对平衡接触角的影响较小。在实验中，XRD检测到的AlN和TiAl3是由于合金与基板接触及N扩散后与合金反应生成，但其生成量很少。
关键字: Ti-Al合金；润湿；氧化；吸附；蒸发
（School of Material Science and Engineering, Chongqing University, Chongqing 400044, China）
Abstract:The wetting behavior of TiN by Ti-Al alloys was studied using an improved sessile drop method at 1758 K. When the mass fractions of aluminum in the alloys are 40%, 50%, 60%, 70% and 80%, the initial contact angle are 68°, 92°, 106°, 140° and 140°, respectively, the initial contact angle has a large dependent on the composition of alloys. When aluminum content is higher than 70%, it could be oxidized to Al2O3 film covering the surface of drop. However, the finial equilibrium contact angles are all less than 20°, which slightly decrease with increasing the aluminum content. The interface after wetting is enriched in high content of titanium and low content of aluminum, no reactant is found. Through calculation, it is known that the chemical potential of titanium in alloys is higher than that in TiN. Under this condition, the titanium is adsorbed on the interface which improves the wetting undoubtedly. In addition, when content of aluminum is higher than 60%, Al will evaporate largely during the final period of spreading, but it has little effect on the variation of contact angle. The AlN and TiAl3 detected by XRD are due to the slightly reaction between alloys and TiN, but the contents are low.
Key words: Ti-Al alloy; wetting; oxidation; adsorption; evaporation
