影响精密铸造件尺(chi)(chi)寸(cun)精(jing)度(du)的(de)要素:普通状(zhuang)况下(xia),精(jing)细铸(zhu)(zhu)(zhu)(zhu)造件(jian)(jian)(jian)(jian)尺(chi)(chi)寸(cun)精(jing)度(du)是受铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)构(gou)(gou)造、铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)材(cai)质、制模、制壳、焙烧(shao)、浇(jiao)注等多方要素影响(xiang)的(de),其中任何一个环节设置、操作不合理都(dou)会使铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)的(de)收(shou)缩(suo)率(lv)产(chan)生变(bian)化(hua),招(zhao)致铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)尺(chi)(chi)寸(cun)精(jing)度(du)与(yu)请求有偏(pian)向。可造成(che🔯ng)精(jing)细铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)尺(chi)(chi)寸(cun)精(jing)度(du)缺(que)陷的(de)要素:铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)构(gou)(gou)造的(de)影响(xiang): 铸(zhu)𒐪(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)壁厚,收(shou)缩(suo)率(lv)大,铸(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)(jian)壁薄(bo),收(shou)缩(suo)率(lv)小(xiao)。
蜡模径向收缩率仅为长度方向收缩率的30-40%,射蜡温度对自在收缩率的影响远远大于对受阻收缩率的影响,温度越高收缩越大。制壳资料的影响:采用锆英砂、锆英粉、上店砂、上店粉,因其收缩系数小,仅为4.6×10-6/℃,因而能够疏忽不计。