| 摘要: | 住友金屬於1936開發了能抗(SCC)的『超超杜拉鋁，ESD（extra super duralumin）』，被用於零式戰鬥機，此為全球首次7000系 (AlZnMgCu) 高強度鋁合金的實用化；自此後，為了滿足航太結構與零組件之應用，陸續開發了更具高比強度、加工性、焊接性、與SCC等之7000系(AlZnMgCu)合金。目前7000系高強度鋁合金製備與使用上面臨三項困擾，分別是(1)低熱加工速率(擠速<0.8mm/s)、(2)無法線上固溶淬火熱處理、及(3) 抗SCC；這些困擾，鋁合金產學界無不企盼能加以克服。 申請人於前導性研究中發現低熱加工速率的起因，是因加工溫度太低(<450℃)所致，當 7000系合金加工溫度大於450℃時，會發生晶界局部融化，導致加工脆裂(即過燒(overheating)脆裂)，而7000系合金在~450℃時，仍具有相當強度，導致熱加工速率偏低，所以要解決此困擾，首先就是要避免晶界局部融化的現象。 而無法線上固溶淬火熱處理的原因，是因合金高淬火敏感性所造成，當合金具有高淬火敏感特性時，將使合金無法形成過飽和固溶體，導致合金強度的下降，所以要解決此困擾，就要降低合金之淬火敏感特性，如此，即使在較低的淬火速率下，也可以獲得過飽和固溶體。 本三年期研究計畫研究，擬嘗試以合金設計原理，搭配各種強化析出熱處理(如T6、T76、RRA等) ，藉由學理探討這兩項困擾，並達到開發滿足航太材料標準(AMS)規範的抗SCC之新合金。分別探討影響7000系合金之(I)高加工溫度的過燒脆裂現象、(II) 淬火敏感性、與(III)抗應力腐蝕(SCC)性，期能完整呈現此一高強度鋁合金之實用特性，此三年計畫案，分別是：第1年: 合金元素與熱處理對鍛造AlZnMgCu合金加工溫度(ie:固溶溫度)之影響第2年: 合金元素與熱處理對鍛造AlZnMgCu合金淬火敏感性( ie:導致無法線上淬火)之影響第3年: 開發可高速熱加工、可線上淬火、並抗SCC的鍛造AlZnMgCu實驗合金 本研究藉由國內航太鋁合金公司實地測試，期能建立國內相關高強度航太鋁合金之應用資訊，期望能對學界與業界提供有價值之學理參考。 ;In 1936, Sumitomo Metal Ltd. developed a thin plate called "extra super duralumin" which was resistant to stress corrosion cracking(SCC), and was later used on a zero-type fighter aircraft. This is the first time 7000 series (AlZnMgCu) high-strength aluminum alloy (HS-7000) be practical. Since then, in order to meet the application of aerospace structure and components, 7000 series (AlZnMgCu) alloys with higher specific strength, processability, weldability , and SCC resistance have been developed. However, three problems in the manufacturing and using of high strength aerospace Al alloy of 7000 (HS-7000) series, namely (1) low hot working rate (extrusion speed <0.8mm / s), (2) inability to perform on-line heat treatment; and (3) resistant to stress corrosion cracking(SCC); The Al industry and academia are all hope to overcome these problems. In our pre-research found that the low hot working rate was caused by the lower working temperature than (<450 °C). The alloys will be partially melted at the grain boundary, if the working temperature is greater than 450 ° C, resulting in the fragility and the cracking. The reason for the inable to perform on-line solution treatment is due to the high quenching sensitivity of the alloy. When the alloy has high quenching sensitivity, the alloy will not form a supersaturated solid solution, resulting in a decrease in the strength of the alloy. It is necessary to reduce the quenching sensitivity of the alloy, so that a supersaturated solid solution can be obtained at a lower quenching rate. Therefore, this study attempts to alloy design principles, with a variety of enhanced precipitation heat treatment (such as T6, T76, RRA, etc.), by theoretical to explore these two problems, anti-stress corrosion and achieve development to meet the criteria aerospace materials (AMS) specification.As mentioned above, based on the process of the HS-7000 AlZnMgCu series (especially 7075) alloy, a three-year research plan is planned to investigate: (I)high hot working temperatures causing overheating of the HS-7000 series alloys, (II)Quenching sensitivity, and (III)resistance to stress corrosion, can fully present the practical characteristics of this high-strength aluminum alloy. The3-year plan is:1st year: Effect of alloying and heat treatments on working temperature (ie: solution temperature) of wrought HS-7000 alloys2nd year: Effect of alloying and heat treatments on quenching sensitivity of wrought HS-7000 alloys (ie: resulting in inable to quench on-line)3rd year: Developed a wrought HS-7000 experimental alloy that can be deformed at high speed, on-line quenched, and SCC resistant. Based on the practical value and process troubles of the above- mentioned This study is expected to develop the wrought HS-7000 experimental alloy, which can be used to establish its application information for aluminum academia and industry to provide the valuable references. |
