本文選題：7075鋁合金 + 擠壓比��； 參考：《江蘇理工學(xué)院》2015年碩士論文

【摘要】：噴射成形技術(shù)制備出的7075鋁合金冶金質(zhì)量相對(duì)較低,因此需要后續(xù)的形變處理及熱處理來提高性能。該材料在擠壓時(shí),擠壓比大小會(huì)對(duì)材料組織產(chǎn)生影響,而材料的組織影響著后續(xù)的熱處理。因此,本文探索了擠壓比大小對(duì)后續(xù)的熱處理的影響,為實(shí)際生產(chǎn)提供理論依據(jù)。本論文主要采用金相、掃描電鏡、X射線衍射及拉伸等測(cè)試手段分析了實(shí)驗(yàn)合金及熱處理后實(shí)驗(yàn)合金的組織性能。研究結(jié)果主要如下:噴射成形坯經(jīng)過不同擠壓比擠壓后,原始晶界消失。隨著擠壓比的增大,晶粒變形程度越大,合金的綜合性能越好。但擠壓比的變化導(dǎo)致了合金內(nèi)部?jī)?chǔ)存能不盡相同,反應(yīng)在合金的再結(jié)晶程度。擠壓比為8擠出的合金經(jīng)固溶510℃×0.5h處理后,發(fā)生完全再結(jié)晶;擠壓比為32擠出的合金經(jīng)固溶460℃×2h處理后,發(fā)生完全再結(jié)晶;擠壓比為60擠出的合金經(jīng)固溶440℃×1h處理后,發(fā)生完全再結(jié)晶。隨著擠壓比的變化,與不同擠壓比擠出的合金匹配的固溶溫度與時(shí)間也發(fā)生了變化。與擠壓比為8擠出的合金匹配的固溶處理工藝是490℃×1h;與擠壓比為32擠出的合金匹配的固溶處理工藝是460℃×1h;與擠壓比為60擠出的合金匹配的固溶處理工藝是435℃×1h。7075鋁合金具有很強(qiáng)的時(shí)效析出強(qiáng)化效果,這適用于不同擠壓比擠出的合金,單級(jí)時(shí)效中,不同擠壓比擠出的合金在120℃×24h時(shí),表現(xiàn)的性能最佳。擠壓比為60擠出的合金由于固溶不充分,組織中殘余第二相數(shù)量多、尺寸大,其性能不如其他擠壓比下合金。雙級(jí)時(shí)效中,終時(shí)效溫度是影響強(qiáng)度、硬度的最大因素,預(yù)時(shí)效溫度是影響伸長(zhǎng)率的最大因素,不同擠壓比合金經(jīng)過雙級(jí)時(shí)效后,與峰值時(shí)效相比,力學(xué)性能均有不同程度的下降。擠壓比為8擠出的合金適宜的雙級(jí)時(shí)效工藝是130℃×4h+150℃×12h;擠壓比為32與60擠出的合金適宜的是130℃×3h+150℃×12h。
[Abstract]:The metallurgical quality of 7075 aluminum alloy prepared by spray forming technology is relatively low, so it is necessary to improve the properties of 7075 aluminum alloy by subsequent deformation and heat treatment. When the material is extruded, the extrusion ratio will affect the microstructure of the material, and the microstructure of the material will affect the subsequent heat treatment. Therefore, the effect of extrusion ratio on subsequent heat treatment is explored in this paper, which provides theoretical basis for practical production. In this paper, the microstructure and properties of the experimental alloy and the experimental alloy after heat treatment were analyzed by means of metallography, scanning electron microscope, X-ray diffraction and tensile test. The main results are as follows: the original grain boundary disappears after different extrusion ratio. With the increase of extrusion ratio, the higher the degree of grain deformation, the better the comprehensive properties of the alloy. However, the change of extrusion ratio leads to different internal storage energy, which is reflected in the recrystallization degree of the alloy. The alloy with extrusion ratio of 8 was treated with solution 510 鈩，

本文編號(hào)：2115278