前言 在航天工业和电子工业中,有许多高频腔体的零件,是采取铸造方法制造的。因为对这些铸件的内在质量要求特别高,如有的零件要求在机加工镀银后不能有任何肉眼可见的小麻点。所以,许多厂普遍地反映铸件的废品率很高,合格率有时低到20％～30％。因此,解决高频腔体铸件的质量问题,是迫在眉睫的问题。 Preface In aerospace and electronics industries, there are many high-frequency cavity parts that are manufactured by casting. Because of the inherent quality requirements of these castings are particularly high, some parts require no macroscopic pockmarks after machining the silver finish. Therefore, many plants generally reflect the rejection rate of castings is very high, the pass rate is sometimes as low as 20% to 30%. Therefore, to solve the quality problems of high-frequency cavity casting is an urgent problem.