Ni/Al层状复合材料的冷加工硬化及热处理软化规律

实验室成功叠轧制备Ni/Al复合材料,研究了叠轧道次和热处理对复合材料硬度的影响规律。结果表明:随着叠轧道次的增加,Ni、Al组元及复合材料硬度均有增大。当叠轧道次n≤3时,Ni组元的层状结构使得Al的变形受到材料整体性的抑制作用,导致了复合材料整体硬度出现反常增大现象;当叠轧道次n>3时,Ni颗粒在Al组元中的镶嵌效应使得Al组元变形所受的抑制作用减弱,从而使得复合材料整体硬度随叠轧道次增加速度减慢。建立了叠轧道次n与Ni、Al组元及复合材料整体硬度的关系方程。经250 ℃×50 min热处理,组元间附加应力的减小和再结晶作用导致Ni、Al组元及复合材料整体硬度减小,且由于变形的不均匀使得Ni层颗粒再结晶程度不均匀,导致Ni组元硬度波动变大。

Cold work hardening and heat treatment softening of multilayered Ni/Al composites

Ni/Al composite was successfully prepared by ARB process in laboratory. Effects of accumulative rolling pass and heat treatment on the hardness of composite were studied. The results show that the hardness of Ni, Al component and composite increases with the increase of rolling passes. The deformation of Al is restrained by the integrity of the material due to the layered structure of Ni component when the rolling pass is less than 3, which leads to the abnormal increase of the overall hardness of the composite. When the rolling pass n>3, the inlay effect of Ni particles in the Al component weakens the inhibition of deformation of Al component, which slows down the increase of overall hardness of the composite. The relationship model of n with Ni, Al component and overall hardness of composite are established. After 250 ℃×50 min heat treatment, the recrystallization and decrease of additional stress result in the decrease of the hardness of Ni, Al and composite materials as a whole; the degree of recrystallization of Ni layer particles is uneven due to the uneven deformation, which makes the hardness of Ni component fluctuate greatly.