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Process for the production of dense sintered shaped articles of polycrystalline boron carbide by pressureless sintering
Process for the production of dense sintered shaped articles of polycrystalline boron carbide by pressureless sintering
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机译:通过无压烧结生产致密的多晶碳化硼烧结成型制品的方法
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摘要
A method of producing dense shaped articles of pure boron carbide that optionally contain 0.1 to 8% by weight of free carbon in the form of graphite is disclosed involving the steps of homogeneously mixing boron carbide in submicron powder form with small quantities of a carbon containing additive, forming the powder mixture into a shaped green body and then sintering the body in a controlled atmosphere and in the absence of external pressure at a temperature of about 2100-2200 C. The shaped articles thus obtained are polycrystalline and, insofar as they correspond to the stoichiometric composition B.sub.4 C, single-phase; they have an average grain size of not more than 10 m, a density of at least 90% of the theoretical density of boron carbide and a flexural strength of at least 300 N/mm.sup.2. The fracture mode of the sintered articles is completely transcrystalline.
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机译:公开了一种生产纯碳化硼的致密成形制品的方法,该制品可选地包含0.1至8重量%的石墨形式的游离碳,该方法包括将亚微米粉末形式的碳化硼与少量含碳添加剂均匀混合的步骤。 ,将粉末混合物制成成形的生坯,然后在受控的气氛中,在无外部压力的情况下,在约2100-2200℃的温度下烧结该坯体。这样得到的成形制品是多晶的,并且在它们对应于化学计量组成B 4 C,单相;它们的平均晶粒尺寸不超过10 m,密度至少为碳化硼理论密度的90%,抗弯强度至少为300 N / mm。烧结制品的断裂模式是完全跨晶的。
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