HMD法制备U-10wt%Mo合金粉末的粒度控制

Granularity Control of U-10wt%Mo Powder Prepared by HMD Method

对氢化-破碎-脱氢（HMD）法制备U-10wt％Mo合金粉末的粒度控制工艺进行了研究。U-Mo合金在950℃分别退火4、10、24h，然后经过γ→α相转变热处理、HMD法和α→γ相转变热处理等过程成为粉末。分析结果表明：950℃下U-Mo晶粒长大较慢，可通过调节保温时间使晶粒尺寸控制在40-100μm；γ相分解程度强烈依赖于晶粒尺寸，晶粒尺寸越大，γ相向α相的转变程度越低；粉末粒度大小与原始合金γ相的晶粒度密切相关，原始合金γ相晶粒度越大，粉末粗粉比重越大。

The granularity control of U-10wt%Mo alloy powder prepared by hydriding-millingdehydriding （HMD） method is introduced in this paper. U-Mo alloy is annealed for 4 h, 10 h and 24 h at 950 ℃. Then U-Mo alloy powder is prepared through the process of γ→α phase transition, hydriding-milling-dehydriding and α→γ, phase transition. Analysis results indicates that the U-Mo grain grows slowly at 950 ℃, and the grain size could be controlled in the range of 40-100 μm by adjusting time. The γ-phase transition is strongly depended on the grain size, and when grain is big, γ→α phase transition is difficult. The powder size is related tightly with the grain size in the initial γ-phase alloy, and when γ-phase grain is big, the mass percent of coarse powder is high.