【摘要】 液压阀体结构复杂,在对阀体的结构特点和铸造难点等分析之后,对多种铸造工艺方法进行了比较,得出用选择性激光烧结(SLS)成形技术烧结覆膜砂,直接制备复杂液压阀体的砂型及砂芯是最佳的方案。激光烧结最佳工艺参数和后固化温度为,预热温度60℃～70℃,激光功率40W,辅粉层厚0.25mm,扫描速度2 500 mm/s,扫描间距0.2mm,后固化温度170℃。通过3次浇注实验,成功解决了浇注过程中发气量大,砂芯细长强度低等难题,得到了合格的HT200液压阀体铸铁件。更多还原

【Abstract】 The structure of hydraulic pressure valve is very complex.The structure characteristics and casting difficulties are analyzed and several casting methods are compared.Our results show that the optimal project is using selective laser sintering technique to sinter the pre-coated foundry sands and directly make the complex hydraulic pressure valve’s sand mode and sand core.The optical sintering parameters are obtained,pre-temperature is 60℃~70℃,laser power is 40 W,powder thick is 0.25 mm;scan speed is 2 500 mm/s;scan space is 0.2 mm,post curing temperature is 170 ℃.Through three times of casting experiments,the problems such as big gas evolution and thin sand core are resolved.At last the eligible HT200 hydraulic pressure valve iron casting part is obtained.更多还原