硬质合金中WC晶面取向分布形成的机理研究

发布时间：2018-01-15 02:24

本文关键词：硬质合金中WC晶面取向分布形成的机理研究　出处：《中国体视学与图像分析》2016年01期 　论文类型：期刊论文

【摘要】：采用本研究组原创的原位合成短流程专利技术,结合制备方案和工艺参数优化,研制出了具有高度WC特征晶面取向分布的WC-Co硬质合金块体材料。利用X射线衍射分析和背散射电子衍射(EBSD)方法对所制备的硬质合金材料的物相组成、取向特征进行了系统的表征研究,同时对WC特征晶面取向分布形成机理从粉末物相组成和烧结过程参数两个方面进行了分析讨论。研究结果表明:WC晶粒呈现明显的板状晶,硬质合金块体在垂直于烧结压力方向上具有WC晶粒基面(0001)择优取向分布,在平行于烧结压力方向上,基面面积分布比例明显减少,相应的出现了WC晶粒柱面(10-10)的择优取向分布。粉末中缺碳相含量和烧结过程中辅助压力的大小对最终制备的合金块体WC晶粒的取向分布起着决定性的作用,缺碳相在烧结的过程中进一步碳化形成板状WC晶粒并在压力的作用下趋于基面垂直于压力方向分布为块体中WC特征晶面取向分布的主要形成机制。
[Abstract]:The original patent technology of in situ synthesis was used in this research group, and the preparation scheme and process parameters were optimized. WC-Co cemented carbide bulk materials with high WC characteristic crystal plane orientation distribution have been developed. X-ray diffraction analysis and backscatter electron diffraction (EBSD) have been used to study the properties of WC-Co cemented carbide bulk materials. Methods the phase composition of the cemented carbide materials was studied. The orientation characteristics were systematically studied. At the same time, the formation mechanism of orientation distribution of WC characteristic crystal plane was analyzed and discussed from two aspects of powder phase composition and sintering process parameters. The cemented carbide block has the preferred orientation distribution of WC grain base plane (0001) perpendicular to the sintering pressure direction, and the proportion of the base surface area distribution decreases obviously in the direction parallel to the sintering pressure direction. The corresponding WC grain columnar surface appears 10-10). The content of carbon-deficient phase in the powder and the size of the auxiliary pressure in the sintering process play a decisive role in the orientation distribution of the final prepared bulk WC grains. In the process of sintering, the carbon deficient phase further carbonizes to form plate-like WC grains and tends to be perpendicular to the pressure direction under the action of pressure, which is the main forming mechanism of the orientation distribution of WC characteristic planes in the bulk.
【作者单位】：北京工业大学材料科学与工程学院/新型功能材料教育部重点实验室;
【基金】：国家杰出青年科学基金(No.51425101) 北京市自然科学基金重点项目(No.2131001)
【分类号】：TG135.5
【正文快照】： 0前言WC-Co硬质合金具有优良的硬度、强度和断裂韧性的力学性能配合,使其在切削刀具和耐磨零部件等领域具有广泛的应用[1-3]。超细晶及纳米晶硬质合金[4-5]理论上具有比常规粗晶硬质合金更为优越的硬度、耐磨性、抗弯强度等力学性能[6],在军工、航空航天等特殊应用领域具有重

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