润滑剂对金属磨具湿法成形组织和性能的影响

为研究不同润滑剂的微观结构和热力学性能及其对湿法成形毛坯或烧结组织的结构和力学性能的影响,在金属磨具中添加不同的润滑脱模剂并以湿法轧制成形和脱脂烧结,使用同步热分析仪、扫描电子显微镜和X射线衍射仪等设备分析试样的性能。结果表明：硬脂酸锌的脱脂残留量（质量分数,下同）约为20.00%,残渣为纳米级颗粒的团聚体,HV1润滑剂的残留量仅为3.00%,残渣为尺寸约10μm的互锁型无规则颗粒;HV1和硬脂酸锌润滑剂均对湿法成形有较好的脱模效果,但添加HV1和硬脂酸锌润滑剂的压坯密度分别降低0.5%和5.0%,烧结样品的密度分别降低1.5%和3.4%,抗弯强度分别降低4.4%和9.1%。相比于硬脂酸锌润滑剂,HV1对压坯和样品性能的影响较小,同时具有较好的脱模效果,更适用于金属磨具各类湿法成形的应用。

Effect of lubricants on microstructure and properties of metal abrasive tools via wet molding

To study the microstructure and the thermodynamic properties of lubricants, as well as their effects on the structure and mechanical property of wet-forming or sintered materials, different lubrication release agents are added into metal abrasive tools which are fabricated with wet forming and degreasing sintering process. Synchronous thermal analyzer, scanning electron microscope and X-ray diffractometer are used to analyze the performance of the samples. The results indicate that the the residual degreasing amount of zinc stearate is about 20.00% while that of HV1 lubricant is only 3.00%. The residue of zinc stearate is the aggregate of nanometer particles and the counterpart of HV1 is ～10 μm interlocking irregular particles. Both HV1 and zinc stearate lubricant have better release effect on wet molding. However, adding HV1 or zinc stearate lubricant reduces the density of the compact by 0.5% or 5%, the density of sintered samples by 1.5% or 3.4%, and the bending strength by 4.4% or 9.1%, respectively. Compared with zinc stearate lubricant, HV1 has good demoulding effect and less influence on the properties of the compact and the sample, which is more suitable for metal abrasives of wet forming applications.