Zhang Yubin, Liao Xinjiang, Lin Qiaoli, Mu Dekui, Lu Jing, Huang Hui, Huang Han
Institute of Manufacturing Engineering, Huaqiao University, Xiamen 361021, China.
School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730000, China.
Materials (Basel). 2020 Mar 27;13(7):1532. doi: 10.3390/ma13071532.
In this work, the reactive wetting and infiltration behaviors of a newly designed Sn-V binary alloy were comprehensively explored on porous graphite for the first time. It was discovered that 0.5 wt.% addition of V can obviously improve the wettability of liquid Sn on porous graphite and the nominal V contents in Sn-V binary alloys has minor effects on the apparent contact angles wetted at 950 °C. Moreover, the V-containing Sn-V alloys were initiated to spread on porous graphite at ~650 °C and reached a quasi-equilibrium state at ~900 °C. Spreading kinetics of Sn-3V alloy on porous graphite well fitted in the classic product reaction controlled (PRC) model. However, our microstructural characterization demonstrated that, besides vanadium carbide formation, the adsorption of V element at the wetting three-phase contact line spontaneously contributed to the reactive spreading and infiltrating of Sn-V alloys on porous graphite. Meanwhile, the formation of continuous vanadium carbides could completely block the infiltration of Sn-V active solder alloy in porous graphite. Affected by the growth kinetics of vanadium carbides, the infiltration depth of Sn-V alloys in porous graphite decreased at increased isothermal wetting temperatures. This work is believed to provide implicative notions on the fabrication of graphite related materials and devices using novel V-containing bonding alloys.
在这项工作中，首次在多孔石墨上全面探究了一种新设计的Sn-V二元合金的反应性润湿和渗透行为。研究发现，添加0.5 wt.%的V能显著提高液态Sn在多孔石墨上的润湿性，且Sn-V二元合金中的名义V含量对950°C下的表观接触角影响较小。此外，含V的Sn-V合金在约650°C时开始在多孔石墨上铺展，并在约900°C时达到准平衡状态。Sn-3V合金在多孔石墨上的铺展动力学很好地符合经典的产物反应控制（PRC）模型。然而，我们的微观结构表征表明，除了形成碳化钒外，V元素在润湿三相接触线处的吸附自发地促进了Sn-V合金在多孔石墨上的反应性铺展和渗透。同时，连续碳化钒的形成会完全阻止Sn-V活性钎料合金在多孔石墨中的渗透。受碳化钒生长动力学的影响，Sn-V合金在多孔石墨中的渗透深度随等温润湿温度的升高而降低。这项工作有望为使用新型含V键合合金制造石墨相关材料和器件提供启示性的思路。
