挤压表面致密化和滚压表面致密化工艺对比

选择表面致密化工艺主要包括挤压致密化和滚压致密化，本文基于表面致密化零件的生产，从零件性能检测方面对比分析挤压致密化和滚压致密化工艺的差异性。试验结果表明：两种工艺制备出的零件在齿廓处均能形成一层均匀的表面致密层，零件的表面强度和表面硬度均得到较大提高；挤压致密化工艺会导致烧结件端面翻边，容易造成后续烧结件外观质量问题，而滚压致密化工艺则不会产生类似外观质量问题；挤压致密化工艺中零件挤压进给量取决于模具尺寸，挤压进给量无法随意调整，并且随着模具径向尺寸的磨损，挤压进给量会变化且不可控，而滚压致密化工艺通过调节两副滚轮模具中心轴的距离，可以快速调整零件滚压进给量，制备出符合要求的表面致密层。因此，滚压致密化工艺优于挤压致密化工艺。

Comparison between extrusion surface densification and rolling surface densification

Selective surface densification process mainly includes extrusion densification and rolling densification.Based on the production of surface densified parts,this paper compared and analyzed the differences between extrusion densification and rolling densification from the aspect of parts performance testing.The experimental results show that a uniform surface dense layer can be formed at the tooth profile of the parts prepared by the two processes,and the surface strength and hardness of the parts are greatly improved.Extrusion densification process will lead to flanging on the end face of sintered parts,which is easy to cause appearance quality problems of subsequent sintered parts,while rolling densification process will not produce similar appearance quality problems.In the extrusion densification process,the extrusion feed depends on the die size,which can not be adjusted at will,and it will change with the wear of the radial size of the die.In the rolling densification process,the rolling feed can be quickly adjusted by adjusting the distance between the central axis of the two roller dies,and the required surface densification layer can be prepared.Therefore,rolling densification is better than extrusion densification.