Influence of Pre-Straining and Pre-Ageing on the Age-Hardening Response of Al-Mg-Si Alloys
Influence of Pre-Straining and Pre-Ageing on the Age-Hardening Response of Al-Mg-Si Alloys
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DOI：
10.4028/www.scientific.net/msf.794-796.903
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发表时间：
2014-06
期刊：
影响因子：
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通讯作者：
Yong Yan;Z. Liang;J. Banhart
中科院分区：
文献类型：
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作者：
Yong Yan;Z. Liang;J. Banhart
采用维氏硬度和差示扫描量热法（DSC）研究了预应变和预时效对Al-0.6%Mg-0.8%Si合金时效硬化响应的影响。研究发现，预时效可以抑制不需要的团簇的形成，并在一定时间内保持结构稳定。预老化治疗可以有效减少或避免自然老化对人工老化的负面影响，甚至产生积极的效果。预应变也可以减少团簇的形成，但团簇的动力学仍然与淬火条件下的相似。相反，预应变后，β和β的峰值位置移动到较低的温度，并且在更短的时间内达到峰值硬度，表明预应变加速了β和β的形成。然而，预应变后自然老化的负面影响仍然存在。预老化之前的预应变可以利用这两种技术并产生积极的强度响应。对于预时效后的预应变，预应变往往会破坏预时效产生的结构的稳定性，并可能重新激活团聚过程，这对后续的人工时效产生负面影响。
The effect of pre-straining and pre-ageing on the age hardening response of Al-0.6%Mg-0.8%Si alloy is studied by Vickers hardness and differential scanning calorimetry (DSC). It is found that pre-ageing can suppress the formation of unwanted clusters and keeps the structure stable for a certain time. A pre-ageing treatment can effectively reduce or avoid the negative effect of natural ageing on artificial ageing and even produce a positive effect. Cluster formation can also be reduced by pre-straining, but the kinetics of clustering is still similar to that of the as-quenched condition. In contrast, after pre-straining, the peak positions of β and β move to lower temperatures and peak hardness is achieved in a shorter time, indicating that the formation of β and β is accelerated by pre-straining. However, the negative effect of natural ageing still persists after pre-straining. Pre-straining before pre-aging can take advantage of both techniques and produce a positive strength response. For pre-straining after pre-aging, pre-straining tends to destabilize the structure created by pre-ageing and can reactivate the clustering process, which has negative effect on subsequent artificial ageing.