喷射共沉积SiC_p增强6061Al MMC的阻尼特性及位错阻尼机制

DAMPING CHARACTERISTIC AND DISLOCATION INDUCED DAMPING MECHANISM OF SPRAY ATOMIZED AND CODEPOSITED 6061Al/SiC p MMC

采用喷射共沉积方法制备了６０６１Ａｌ／ＳｉＣｐＭＭＣ，并对其阻尼机制进行了研究。发现在试验测量范围内Ｑ－１对ｆ和ｔ敏感，对Ａｍ没有依从性，Ｍ随ｔ变化只表现为线性下降，无明显软化现象，且６０６１Ａｌ／ＳｉＣｐＭＭＣ的阻尼能力比６０６１Ａｌ至少高一个数量级。６０６１Ａｌ／ＳｉＣｐＭＭＣ在试验测量温度范围内，位错阻尼起主要作用。在低应变条件下，随温度的升高，由于热激活作用，位错阻尼在不同的温度段表现出不同的作用机制，可描述为：位错弓出→溶质原子和气团协同位错运动→位错从溶质原子脱钉并拖曳气团运动→长位错摆脱气团在强钉扎下运动→位错脱钉。

In order to obtain a high damping capacity aluminum matrix composites, 6061Al/SiC p MMC was fabricated by spray atomization and codeposition, and the damping mechanism of the material was studied. The results show that the damping capacity Q -1 is sensitive to f and t , but is not related with A m; and M decreases linearly with increasing t and is not obviously soft during the experimental testing range. The damping capacity of 6061Al/SiC p MMC is ten times higher than that of 6061Al. The dislocation induced damping is the main mechanism of 6061Al/SiC p MMC. Under low strain with increasing temperature, for thermal activation the dislocation induced damping shows various effecting mechanism, which can be described as follows: pinned dislocation line bowes out→the motion of dislocation line is followed by the solution atoms and interstitial atom atmosphere→the motion of dislocation line breaks out from the solution atoms and drags the atmosphere→the motion of long dislocation breaks from the atmosphere and is pinned by some powerful pinning points→the pinned dislocation line breaks away.