EFFECT OF REINFORCEMENT ON THE AGING RESPONSE OF CAST 6061 AL-AL2O3 PARTICULATE COMPOSITES
EFFECT OF REINFORCEMENT ON THE AGING RESPONSE OF CAST 6061 AL-AL2O3 PARTICULATE COMPOSITES
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DOI：
10.1007/bf02851349
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发表时间：
1991-11-01
期刊：
影响因子：
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通讯作者：
HAFLEY, JL
中科院分区：
文献类型：
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作者：
DUTTA, I;ALLEN, SM;HAFLEY, JL
采用显微硬度、电阻率、差示扫描量热法和透射电子显微镜（TEM）研究了10和15体积%氧化铝颗粒添加对铸造6061铝基复合材料时效硬化行为的影响。 结果发现，在基体合金中的沉淀的动力学显着加速，由于存在的增强。 这种加速可归因于成核所需的孵育时间的减少和溶质扩散率的增加，因此沉淀物生长速率由基体位错密度的增加引起，基体位错密度的增加是由于基体和增强体之间的热膨胀系数（CTE）失配。 还观察到各相的相对量受增强添加的影响。 增强体含量的增加降低了β '和β-析出物的体积分数，同时增加了GP-I区的体积分数。 硅团簇（这是前体GP区在6061铝）形成后固溶处理老化过程中的体积分数被发现减少，增加钢筋此外。 对上述效应的相关机制进行了讨论，并给出了合理的解释。
The effect of 10 and 15 vol pct alumina particulate addition on the age hardening behavior of cast 6061 Al-matrix composites was studied using microhardness, electrical resistivity, differential scanning calorimetry, and transmission electron microscopy (TEM). It was found that the kinetics of precipitation in the matrix alloy are significantly accelerated due to the presence of reinforcements. This acceleration is attributable to the decrease in incubation time required for nucleation and the increase in solute diffusivity and hence precipitate growth rate resulting from the increase in the matrix dislocation density due to coefficient of thermal expansion (CTE) mismatch between the matrix and the reinforcements. The relative amounts of the various phases were also observed to be affected by reinforcement addition. Increasing reinforcement content decreased the volume fractions of the beta' and beta-precipitates while increasing the volume fraction of the GP-I zones. The volume fraction of silicon clusters (which are the precursors to GP zones in 6061 Al) formed during postsolution treatment aging was found to decrease with increasing reinforcement addition. The above effects have been discussed with respect to the associated mechanisms, and plausible explanations have been offered.