Methods Conventional gypsum-bonded investment(CRISTOBALITE P(CBP))and two kinds of rapid burnout gypsum-bonded investments(CRISTOBALITE PF(CBPF) and CRISTQUICK 20(CQ)) were employed.

• 方法选用传统型石膏包埋料CRISTOBALITE P(CBP)、快速加热型石膏包埋料CRISTOBALITE PF(CBPF)和CRISTQUICK20(CQ)。