B的计算纯度对TiB_2-Cu复合材料的影响  

Influence of calculated purity of boron powder on TiB_2-Cu composites

作　　者：徐强[1] 张幸红[1] 韩杰才[1] 赫晓东[1] 

机构地区：[1]哈尔滨工业大学复合材料研究所,黑龙江哈尔滨150001

出　　处：《材料科学与工艺》2003年第3期284-287,共4页Materials Science and Technology

基　　金：教育部博士点基金(20020213037);航天创新基金(2002-2004年度).

摘　　要：用SHS工艺制备了TiB2-Cu复合材料,研究了B的4组计算纯度90%、92%、95%和100%对复合材料的相对密度、相组成、微观组织、弯曲强度和断裂韧性的影响.结果发现TiB2-Cu复合材料的综合性能在B计算纯度为92%时最好,而并非实际纯度90%.基于B与粉末中的杂质O反应生成B2O3而挥发掉的原理,得出产生这种结果的原因主要是:B的计算纯度越低,表明B的实际含量越高,但同时相应的杂质含量也越高,这样由于杂质的挥发而产生的孔隙也越高;一小部分Ti在高温下固溶于基体Cu中而消耗Ti,使B剩余,所以在计算配比时,B的计算纯度应大于实际纯度,但是考虑到两种原因的综合作用,应存在一个最佳的计算纯度.TiB2-Cu composites were fabricated by Self-propagating High-temperature Synthesis (SHS). The effects of four kinds of calculated purities of boron powder: 90%, 92%, 95% and 100%, on relative density, phase composition, microstructure, bending strength and fracture toughness of TiB2-Cu composites were studied. The results showed that the combination property of TiB2-Cu composites is the best when calculated purity of boron is 92%, not the actual purity of boron, which is 90%. Based on the principle that boron and oxygen impurity among the powders reacted to form volatile B2O3, two reasons from analysis can be obtained: the lower the calculation purity of boron is, the higher the actual content of boron and the impurity are. Higher impurity content can bring higher porosity. On the other hand, a little titanium dissolves into copper matrix at high temperature with the result that titanium is consumed and boron is residual. It is considered that calculation purity of boron should exceed its actual purity. Considering the combination effects of two reasons, the calculated purity of boron, of 92%, is the best one.

关 键 词：计算纯度 TIB2-CU复合材料 B 性能 粉末 杂质 自蔓延燃烧合成 SHS 

分 类 号：TB33[一般工业技术—材料科学与工程]