不同碳气氛对TiC-FeCrMo硬质合金组织及抗弯强度的影响

Influence of Carbon Atmosphere on Microstructure and Bending-Strength of TiC-FeCrMo Hard Alloy

采用粉末冶金工艺制备了Fe-2.0Cr-2.0Mo-0.3C-35TiC钢结硬质合金。在1425～1455℃范围内研究了不同碳气氛对合金密度和抗弯强度的影响。不同碳气氛采用不同装舟方式来控制,即样品掩埋入TiC填料方式、样品曝露于Al2O3+4%C填料之上、样品与Al2O3+4%C之下铺一层碳黑并曝露方式。通过OM、SEM观察了合金的微观组织形貌;通过EDX手段分析了合金中各相的组成成分;测量了合金的密度和抗弯强度。结果表明,采用样品与Al2O3+4%C之下铺一层碳黑并曝露方式能够提供充足的碳气氛,改善液态Fe与TiC微粒的润湿性,1435℃下烧结1h所得的试样具有理想的致密度和抗弯强度,其密度达6.51g.cm-3,抗弯强度达1659MPa,比目前国内生产的相近成分的合金抗弯强度提高了约22%。

Fe-2.0Cr-2.0Mo-0.3C-35TiC steel-bonded titanium carbide was prepared by powder metallurgy. The influence of three different types of loading on the density and bending strength of the sintered alloy was studied at different sintering temperatures in the range of 1425~1455 ℃. The 1st type of loading was that the alloy was entirely buried directly in the TiC filling,and the 2nd type of loading was that the alloy was placed on top of the Al2O3+4%C filling,not buried but exposed,while the 3rd type was that the ...