本文選題：7A04鋁合金 + 擠壓��； 參考：《南京理工大學(xué)》2017年碩士論文

【摘要】：本文以雙錐薄壁7A04鋁合金零件為主要研究對(duì)象,在預(yù)先確定擠壓成形方案、坯料類型和工藝參數(shù)范圍的基礎(chǔ)上,利用有限元模擬軟件Deform-3D分析雙錐薄壁零件成形過(guò)程中內(nèi)部金屬流動(dòng)規(guī)律、載荷變化情況、各種場(chǎng)量分布等,同時(shí)研究變形溫度、坯料形狀尺寸、變形速度、潤(rùn)滑條件等因素對(duì)成形結(jié)果的影響規(guī)律,確定最佳的擠壓工藝參數(shù)。參照YST 591-2006變形鋁及鋁合金熱處理規(guī)范,根據(jù)零件預(yù)期達(dá)到的力學(xué)性能要求,確定熱處理工藝參數(shù)范圍。對(duì)擠壓好的零件進(jìn)行不同方式固溶處理和不同工藝時(shí)效處理,通過(guò)觀察金相組織、進(jìn)行室溫拉伸試驗(yàn)比較力學(xué)性能,確定最合適的熱處理工藝參數(shù)。結(jié)果表明:相比于柱狀坯料和帶孔板材坯料,管狀坯料成形時(shí)所需的載荷最小,且成形后零件整體的等效應(yīng)變最小,變形最均勻,最終確定選用尺寸為內(nèi)徑31mm,厚度10mm,高度76.5mm的管狀坯料。綜合對(duì)所有模擬結(jié)果的分析和比較,最終確定擠壓溫度為485℃,擠壓速度分為兩段,前120mm行程的擠壓速度為20mm/s,之后行程的擠壓速度為5mm/s。固溶處理可以使7A04鋁合金基體中的第二相溶解更充分,在隨后的時(shí)效過(guò)程中,合金通過(guò)沉淀強(qiáng)化使強(qiáng)度得到大幅度提高。固溶溫度和時(shí)效溫度對(duì)合金強(qiáng)度的影響較大,隨著固溶溫度升高,基體中的第二相數(shù)量變少,顆粒變小,合金過(guò)飽和程度提高,但晶粒發(fā)生不同程度的長(zhǎng)大。經(jīng)過(guò)綜合對(duì)比,合金經(jīng)過(guò)460℃C,1h+480℃C,1h雙級(jí)固溶處理和120℃C,16h時(shí)效后,獲得的性能最好,抗拉強(qiáng)度達(dá)到最大值659.6MPa,此時(shí)Rp0.2=608.8MPa,A=12.79%。
[Abstract]:In this paper, the two-cone thin-walled 7A04 aluminum alloy parts are taken as the main research object, on the basis of the pre-determination of extrusion scheme, blank type and process parameter range, the main research object is the two-cone thin-walled 7A04 aluminum alloy parts.The finite element simulation software Deform-3D is used to analyze the metal flow law, load change, distribution of various fields and so on in the forming process of two-cone thin-walled parts. At the same time, the deformation temperature, blank shape and size, deformation speed, etc are studied.The influence of lubrication conditions on the forming results was studied, and the optimum extrusion parameters were determined.According to the heat treatment specifications of YST 591-2006 deformed aluminum and aluminium alloys, the range of heat treatment process parameters is determined according to the mechanical properties of the parts expected to be achieved.The extruded parts were treated with different methods of solution treatment and different aging processes. By observing the metallographic structure and comparing the mechanical properties with tensile tests at room temperature, the most suitable heat treatment parameters were determined.The results show that, compared with the cylindrical blank and the blank with holes, the tubular blank needs the least load, and the equivalent strain of the whole part after forming is the least, and the deformation is the most uniform.The final size is 31 mm, thickness 10 mm, height 76.5mm tube blank.According to the analysis and comparison of all the simulation results, the extrusion temperature is 485 鈩，

本文編號(hào)：1742586