composite billet meaning in English

双金属坯
组合坯料

We analyze the microstrain and density changing of the composite powders during pressing . the density evolution of ti / al composite billet became calm when the pressure get to 1000mp . the technique of vacuum degassing can reduce the content of atmosphere
分析了复合粉在冷压制过程中的微观变形过程,不同压力下的密度变化趋势,表明在冷压制压力达到1000mpa后复合粉预制坯密度变化趋于平稳。