Ni的添加对TiB2-CU基复合材料微观组织的影响

利用燃烧合成工艺原位合成了TiB2-Cu基复合材料，为了改善TiB2陶瓷和Cu基体的润湿性，将金属Ni作为合金化元素加入到TiB2-Cu复合材料。通过XRD，SEM，EPMA和TEM等检测手段对金属Ni的添加对TiB2-Cu基复合材料微观组织的影响进行了研究。结果表明，含Ni复合材料的金属粘结相的面间距比不含Ni时Cu的面间距均有不同程度的减小；Ni加入后，TiB2-Cu-Ni复合材料的组织较TiB2-Cu复合材料更加致密，但陶瓷颗粒尺寸却大于TiB2-Cu复合材料的颗粒尺寸；Ni的加入降低了复合材料的导热率和冷却速度，使得部分TiB2陶瓷颗粒有足够的时间长成棒状，同时造成TiB2陶瓷颗粒间形成更多的烧结颈；Ni的加入也改善了陶瓷与金属粘结相之间的润湿性，使陶瓷相与金属粘结相的界面结合牢固，看不到TiB2-Cu复合材料中界面脱开的现象。金属Ni的添加有利于改善TiB2-Cu基复合材料的微观组织，进而利于复合材料的致密化。

Effect of Ni Additive on the Microstructure of TiB2-Cu Matrix Composites

TiB_2-Cu matrix composites were in-situ produced via combustion synthesis.Nickel, as an alloy element, was added into TiB_2-Cu composite to improve the wettability between titanium diboride and copper matrix.The effect of nickel additive on the microstructures of TiB_2-Cu matrix composites was investigated using XRD, SEM, EPMA and TEM.The results show that the face spaces of metal binder in TiB_2-Cu-Ni composite are lower than those in TiB_2-Cu composite.With the addition of nickel, the microstructure of TiB_2-Cu-Ni composite is denser than that of TiB_2-Cu composite, while the size of TiB_2 particles is larger than that in TiB_2-Cu composite.Some TiB_2 particles have enough time to grow in block-like shape because the thermal conductivity and cooling rate of composite reduce with the addition of nickel.Moreover, more sintering-necking between TiB_2 particles and particles are formed in TiB_2-Cu-Ni composite.The interfacial bonding between TiB_2 and metal binder is good and no interfacial debonding or interface crack is found in TiB_2-Cu-Ni composite due to improvement of wettability between TiB_2 and metal binder.The research has led to the discovery of improvement of microstructure and densification of TiB_2-Cu matrix composites due to the addition of nickel.