碳化硼微孔喷嘴的注射成形工艺及其表面质量

Process and Surface Quality of Injection Molded Boron Carbide Nozzle with Micro Multi-holes

利用粉末注射成形工艺制备碳化硼微孔喷嘴。研究了注射、脱脂和烧结工艺对碳化硼微孔喷嘴的微观形貌和成形质量的影响。结果表明,当模具温度为60℃、注射压力为100MPa、注射温度为175℃的情况下,微孔喷嘴得到良好的填充。脱脂后制品未发现裂纹和翘曲。随着烧结温度的升高,微孔喷嘴的致密度和线性收缩先增加后减小,表面粗糙度先减小后增加,在1950℃烧结后,微孔喷嘴的烧结性能和力学性能最好,致密度、线性收缩、维氏硬度和表面粗糙度值分别为97.1%,18.7%,3580HV和6.17μm。

Boron carbide nozzle with micro multi-holes was fabricated by powder injection molding.The effects of injection molding,debinding,sintering on microstructure and forming quality of boron carbide nozzle were investigated.The results show that boron carbide nozzle can be filled completely with appropriate molding parameters in mold temperature of 60℃,injection pressure of 100 MPa and nozzle temperature of 175℃.Cracks and warps are not found on the surface of debound product.Densities and linear shrinkages of boron carbide nozzle begin to increase and then decrease with the increasing of sintering temperature,however,the values of surface roughness begin to decrease and then increase.Boron carbide nozzle achieves the best forming and mechanical performances after sintering at 1950℃ of which the density,linear shrinkage,Vickers hardness and value of surface roughness are 97.1%,18.7%,3580HV and 6.17μm,respectively.