PREPARATION OF FUNCTIONALY GRADED MATERIALS USING THE MECHANICALY ALLOYED METALIC-POWDER AND ITS MECHANICAL PROPERTIES

将不同含量的Ti/B=1/2摩尔比的钛和硼粉与铜和铝粉混合，并对混合物进行不同磨矿时间的机械合金化。形成过饱和的铜和铝基体相，基体相的晶粒尺寸达到纳米级。采用x射线衍射小角散射技术研究了时效处理后合金粉末的显微组织变化。在时效处理初期，机械合金化Cu-Ti-B粉末形成调制结构。经过长时间时效处理，Cu-Ti-B和AL-TI-B合金机械合金化粉末中形成TiB_2、TI_2 B_5和Ti_3 B_4等硼化钛相。从真空热压过程中各合金层的致密性、机械强度和显微组织变化的角度估计了作为功能材料的层状致密材料的固结情况。真空热压成形的片层致密均匀，无弯曲轮廓，在较低的温度下处理时间比常规烧结后冷压短。在真空气氛下热压的压片机具有较高的弯曲断裂强度。

Titanium and boron powders were mixed various contents of molar ratio Ti/B=1/2 to copper and aluminum powders and the mixture was mechanically alloyed for various milling periods. The copper and aluminum matrix phases super-saturated with are formed and the ciystalline size of matrix phases became to nanometer order.Microstructural changes in the alloy powder with the age treatment were investigated by small-angle scatter technique in the X-ray diffraction. In an early stage of the age treatment for the mechanically alloyed Cu-Ti-B powder forms a modulated structure. After the age treatment for long time, titanium boride phases such as TiB_2, TI_2 B_5 and Ti_3 B_4 form in the mechanically alloyed Cu-Ti-B and AL-TI-B alloy powders.Consolidation of the lamellar compact as functionally material was estimated from standpoints of densification and mechanical strength of the compact and microsti-ructural change in the each alloy layer during vacuum hot pressing. The lamellar compact is homogeneously densely formed without curved contours by the vacuum hot pressing for shorter treating time at lower temperature than conventional sintering after cold compacting. The lameller compact hot-pressed in the vacuum atmosphere has high rupture strength in the bending.