| dc.description.abstract | Aluminum-based Al-Mg-Si ternary alloys are must wisely used in applications. However, it should easily be form for makers and safety be used for users.
First, we choose the different making process of AA6022 and observe the bending test results. For example the different soaking temperature, the different hot rolling temperature, the different cold rolling reduction ratio, the different solid solution temperature, the different quench rates, the different step quench temperature and the different natural aging time. The analysis styles were by using differential scanning calorimetry (DSC)and by tensile tests, and confirmed by structure observation using transmission electron microscope(TEM) and optical microscopy(OM).
The results indicate that the small grain size and less precipitation aid nice bending status. So, the best experiment process of AA6022 are soaking at 530℃for 14hrs,hot rolling at 480℃,with cold rolling reduction ratio at 70%,quenching into water at room temperature ,then bending formed as quickly as possible.
Second, the precipitation behaviors of AA6061, AA6063 and AA6N01 during Pre-aging and age-hardening after artificial aging were analyzed by using DSC, TEM, bending tests ,tensile tests and measuring the resistivity.
The results indicate that pre-aging at 20℃with the low strength but bad bending status. For tensile tests results, the precipitation of GP Zone(I) form easily at 20℃ ,arrest the GP Zone(II) form during artificial aging . For bending tests ,however, the grain boundary precipitation particles were larger at pre-aging temperature 20℃ than at 0℃and 10℃.Because the large grain boundary particles are easily become the break point.
Final, discuss the extrusion material of AA6063 and AA6N01 with quenching by different styles：water quenching, air quenching and natural quenching. Besides , discuss the Cr and Zr bearing in AA6063 and AA6N01,that form dispersoid Al18Cr2Mg3 and Al3Zr can avoid the grain grow when the recrystallization happened.
The results indicate that natural quenching style will have well bending status because the less GP Zone (II) advent during artificial aging. Allowedly the strength of material quenching by natural cold is not well to be accepted. As regards Cr and Zr bearing in AA6063 and AA6N01,they widely improver the bending status. | en_US |