TiCp/W金属基复合材料的制备与性能研究

Study on Preparation and Properties of TiCp/W Metal Matrix Composite

摘要:

采用滴定法，在偏钨酸铵（AMT）饱和溶液与碳化钛（TiC）微粉和分散剂组成的悬浮液中，滴入无水乙醇获得AMT包覆碳化钛前驱体；然后对前驱体进行高纯氢还原制备出钨包覆TiC复合粉体，对复合粉体进行了XRD物相和SEM形貌分析。结果表明，当N,N-甲基甲酰胺(DMF)和聚乙二醇(PEG)作为TiC与AMT饱和溶液的分散剂，经600 ℃保温1 h和800 ℃保温30 min H2还原，得到分散良好的类球形复合粉体。采用放电等离子体烧结（SPS）技术制得块体样品，对其进行了SEM形貌分析，并测试了其相对密度和力学性能。结果表明，在1600 ℃，保温2 min，SPS烧结后， TiC在基体中分布均匀，TiCp/W复合材料的相对密度达到94.6%，抗弯强度达到739 MPa，显微硬度达到4.86GPa，断裂韧性达到7.87MPa?m1/2。

Abstract:

The precursor of ammonium metatungstate(AMT) coated titanium carbide(TiC) were prepared by titration method, in which the suspension composed of the saturated solution of AMT, TiC micropowder and the dispersants was titrated with the anhydrous ethanol. The as-synthesized precursors were reduced in high-purity hydrogen atmosphere and then the tungsten coated TiC composite powder was prepared. The as-prepared powder was characterized by XRD and SEM. The results showed that the well-dispersed globularlike composite powders were produced when N,N-dimethyl formamide (DMF) and PEG used as the dispersant for TiC and saturated solution of AMT and the precursor reduced in the high-purity hydrogen atmosphere at 600 ℃ for 1h and 800 ℃ for 30 min. And the bulk samples were prepared by spark plasma sintering (SPS) and their SEM morphology, relative density and mechanical properties were investigated. The results showed that TiC particles were uniformly distributed in the matrix W when the samples sintered by spark plasma sintering (SPS) at 1600 ℃ for 2 min, that the relative density, flexural strength, micro-hardness and fracture toughness of the samples achieved 94.6 %, 739 MPa, 4.86GPa and 7.87MPa?m1/2, respectively.