預時效和自然時效對6066與6082鋁合金人工時效硬化行為之影響
Journal
金屬熱處理
Journal Issue
164
Start Page
51
End Page
63
Date Issued
2025-03
Author(s)
吳浩宇
Abstract
在車輛板金應用中，為了使鋁合金強度上升，工廠會實施固溶、淬火與析出強化熱處理，而在固溶熱處理且淬火後之存放與運輸，即，自然時效之導入，將會在汽車板金高溫烤漆後，產生自然時效之負面效應，造成鋁合金強度不如預期。本實驗將利用多種熱處理，從而驗證6066與6082鋁合金之自然時效負面效應，接著導入各式預時效參數，分析其減緩負面效應之效力，並且從各種熱處理參數中，比較6066與6082鋁合金在析出行為與機械性質上之差異。驗結果顯示，6066與6082鋁合金經固溶熱處理並淬火到室溫後，大量的Mg2Si顆粒溶回並形成過飽和固溶體造成鋁晶格扭曲。自然時效對烘烤硬化有明顯的負面影響，而對尖峰時效則不具明顯效應，相較於6082，6066鋁合金在烘烤硬化後具有較嚴重的自然時效負面效應。在自然時效之前進行120℃x1小時的預時效處理有效地減少了自然時效對烘烤硬化的負面影響，6066鋁合金之硬度縮減率從14.8%降至1.4%，而6082合金則從9.6%降至3.7%。
In the context of vehicle sheet metal applications, factories implement solution treatment, quenching, and precipitation hardening heat treatments with the objective of increasing the strength of aluminum alloys. However, the introduction of natural aging during storage and transportation after solution treatment and quenching can give rise to negative effects of natural aging following high-temperature paint baking, which in turn can result in a lower-than-anticipated strength of the aluminum alloy. The objective of this experiment is to ascertain the negative effects of natural aging on 6066 and 6082 aluminum alloys through the utilization of diverse heat treatments. Subsequently, an array of pre-aging parameters will be introduced to evaluate their efficacy in attenuating these negative effects. Additionally, the dissimilarities in precipitation behavior and mechanical properties of 6066 and 6082 aluminum alloys under various heat treatment parameters will be contrasted. The experimental results demonstrate that following solution heat treatment and quenching to room temperature, a considerable quantity of Mg_2Si particles undergo dissolution, thereby forming a supersaturated solid solution that induces distortion of the aluminum lattice. The process of natural aging has a considerable detrimental impact on bake hardening, yet it exerts no discernible influence on peak aging. In comparison to 6082, the 6066 aluminum alloy displays a more pronounced detrimental impact of natural aging following bake hardening. The application of a pre-aging treatment at 120°C for one hour prior to the onset of natural aging has been demonstrated to be an effective method for mitigating the negative effects of natural aging on bake hardening. The reduction in hardness of the 6066 aluminum alloy was reduced from 14.8% to 1.4%, while that of the 6082 alloy was reduced from 9.6% to 3.7%.
Subjects
6000系列鋁合金
銅溶質效應
自然時效負面效應
預時效熱處理
烘烤硬化
6000 series aluminum alloys
Copper solute effects
Negative effects of natural aging
Pre-aging heat treatment
Bake hardening
Type
journal article