α-ZrW_2O_8/Cu复合材料的制备、微观结构和致密度

Preparation,microstructure and densification of α-ZrW_2O_8/Cu composite

采用粉末冶金法制备了ZrW2O8/Cu复合材料.将所制备的ZrW2O8/Cu复合粉体在300-600MPa压制成型,在H2和N2惰性还原混合气氛下600℃烧结2 h后获得含有不同体积分数α-ZrW2O8的α-ZrW2O8/Cu复合材料.XRD分析结果表明,在ZrW2O8表面包覆铜后进行烧结和后热处理所获得的α-ZrW2O8/Cu复合材料中,未发现因热应力产生的γ-ZrW2O8和杂相,有效减小了因ZrW2O8相变而导致其负热膨胀效应的降低.研究结果表明,α-ZrW2O8能均匀分布在Cu基体中.随着压力的提高和Cu的增加,复合材料的致密度提高至88.9%.

ZrW2O8/Cu composites were prepared by the powder metallurgic method.The pre-prepared copper coating ZrW2O8 powders were put into the mould,pressed at 300~600 MPa and sintered at 600 ℃ for 2 h with the mixed hydrogen and nitrogen gases.The α-ZrW2O8/Cu composites with a different volume ratio of ZrW2O8 were then obtained.X-ray diffraction pattern shows that γ-ZrW2O8 induced by thermal stress and impurities are not shown in the composite prepared by this modified method,which effectively decreases the negative effect of ZrW2O8 induced by phase transition.The results show that α-ZrW2O8 can be homogeneously distributed in copper matrix.With the increase of pressure and copper,the densification of composite is also increased to 88.9%.