铸造烧结法制备表面铁基复合材料的致密化机理及耐磨性能
Densification Mechanism and Wear Resistance of Fe Matrix Surface Composite Produced by Cast Sintering Technology
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摘要: 用SEM、XRD等分析了用铸造烧结法在HT200灰铸铁表面制备的复合材料的组织与物相组成,用EDS分析了该复合材料与基体结合界面的元素分布,分析了其致密化机理;测试了此复合材料的耐磨性能.结果表明:在铸造烧结过程中,压坯中的σ-(FeV)相迅速分解出α-Fe和钒,V8C7相的强放热反应及铁液传递给压坯的热流密度保证了压坯迅速完成烧结致密化,得到由微米V8C7颗粒和α-Fe相组成的复合材料,增强相颗粒与基体相结合良好;复合材料与灰铸铁形成了冶金结合;在重载、干滑动摩擦条件下,此复合材料的耐磨性比淬火45钢提高了44.5倍.Abstract: The microstructure and phase composition of the composite on gray cast-iron HT200 surface prepared by cast sintering technology was analyzed by using SEM and XRD.The elementary distribution between surface composite and matrix metal was analyzed by using EDS.The wear-resistance of Fe matrix composite surface was examined.The densification mechanism was analyzed.The results show that the σ-(FeV) phase in the compacts was decomposed into α-Fe and V during the cast sintering process.The high exothermic reactions of the V8C7 phase and the thermal flow transferring from the liquid iron to the compacts guaranteed the compacts densification during sintering,the composite composed of micro V8C7 particles and α-Fe phase could be obtained.The strengthening phase particles combined with the matrix well,the composite and the gray cast-iron was metallurgical binding.The wear-resisting property of the surface Fe matrix composite increased by 44.5 times than that of quenched steel under the condition of heavy load and dry sliding friction.
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