Comprehensive Investigations of the Supersolidus Liquid-Phase Sintering of Two Plastic Mold Steels
Comprehensive Investigations of the Supersolidus Liquid-Phase Sintering of Two Plastic Mold Steels
复制标题
两种塑料模具钢超固相线液相烧结的综合研究
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
W. Theisen
中科院分区：
文献类型：
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作者：
H. Hill;S. Weber;S. Siebert;S. Huth;W. Theisen
塑料加工，特别是增强复合材料，需要在与聚合物接触的工具上使用耐腐蚀和耐磨材料。对于这样的应用，开发了塑料模具钢，其不仅由于马氏体基质中存在碳化物而提供良好的耐磨性，而且主要由足够量的溶解铬提供良好的耐腐蚀性。这些高合金材料的常见加工路线是气体雾化粉末的热等静压（HIP）（PM-HIP）。在这种情况下，烧结起着微不足道的作用，除了金属基复合材料（MMCs）的加工。新型耐磨耐蚀金属基复合材料的开发需要了解这种工具钢预合金粉末的烧结行为。众所周知，合金粉末可以通过超固相线液相烧结（SLPS）来加工，该方法导致几乎完全致密化和微观结构而没有显著的粗化效应。本研究利用计算热力学、热分析、烧结实验及显微组织分析等方法，对两种不同的塑胶模具钢气体雾化粉末进行了研究。结果表明，这两种粉末都可以通过SLPS在真空或氮气气氛中烧结到几乎全密度（1至3%的孔隙率）。致密化行为，氮的吸收，和碳化物体积分数的实验结果是在良好的协议与计算热力学进行的计算。
The processing of plastics, particularly reinforced composites, necessitates the use of corrosion- and wear-resistant materials for tools that come into contact with the polymer. For such applications, plastic mold steels were developed that offer not only a good wear resistance due to the presence of carbides in a martensitic matrix, but also good corrosion resistance provided primarily by a sufficient amount of dissolved chromium. The common processing route for these high-alloyed materials is the hot isostatic pressing (HIP) of gas-atomized powders (PM-HIP). In this context, sintering plays an insignificant role, except for the processing of metal-matrix composites (MMCs). The development of novel wear- and corrosion-resistant MMCs based on plastic mold steels requires knowledge of the sintering behavior of prealloyed powders of such tool steels. It is well known that alloyed powders can be processed by supersolidus liquid-phase sintering (SLPS), a method leading to almost full densification and to microstructures without significant coarsening effects. In this work, two different gas-atomized powders of plastic mold steels were investigated by computational thermodynamics, thermal analysis, sintering experiments, and microstructural characterization. The results show that both powders can be sintered to almost full density (1 to 3 pct porosity) by SLPS in a vacuum or a nitrogen atmosphere. Experimental findings on the densification behavior, nitrogen uptake, and carbide volume fractions are in good agreement with calculations performed by computational thermodynamics.