本文選題：攪拌摩擦焊　切入點：隔熱攪拌頭　出處：《浙江理工大學》2017年碩士論文　論文類型：學位論文

【摘要】：攪拌摩擦焊是一種焊接過程中被焊材料不發(fā)生熔化的固相焊接技術,具有能量利用率高、焊接過程不產生有害氣體、不產生廢料等優(yōu)點,并解決了傳統(tǒng)熔焊易產生焊接缺陷、焊接接頭強度低等缺點,其尤其適合用于焊接如鋁合金、鎂合金等硬度及熔點較低的金屬。目前針對攪拌摩擦焊的研究主要集中在焊接工藝參數(shù)的優(yōu)化設計、攪拌頭設計、焊接過程中材料流動機理、產熱機理,以及其對被焊材料組織和性能的影響等方面。本文利用實驗和計算機模擬相結合的方式研究攪拌摩擦焊接過程中攪拌頭向主軸方向的傳熱,設計制作隔熱攪拌摩擦焊接攪拌頭,減少焊接過程中攪拌頭向主軸的傳熱,降低主軸溫度,同時減少焊接時的熱損耗,提高焊接熱效率。本文借助有限元數(shù)值模擬,設計了一種有利于減少傳熱的新型攪拌頭結構,并采用等離子噴涂法對攪拌頭夾持柄部位噴涂Y2O3穩(wěn)定的Zr O2熱障涂層減少其向主軸方向傳熱,分別使用常規(guī)攪拌頭和本研究所設計的隔熱攪拌頭對5mm厚6061-T6鋁合金板進行焊接實驗,測量焊接過程中攪拌頭、機床主軸以及焊接試板的溫度場,研究隔熱攪拌頭的隔熱效果并計算焊接熱效率。實驗結果表明,在攪拌頭旋轉速度800 r/min,焊接速度30 mm/min的情況下,使用常規(guī)攪拌頭焊接主軸外表面穩(wěn)態(tài)溫度最高為82.8℃,使用隔熱攪拌頭最高為43.1℃,溫度降低顯著,有限元數(shù)值模擬結果表明,在以上條件下,使用常規(guī)攪拌頭焊接向主軸方向傳熱功率為88.4W,使用隔熱攪拌頭傳熱功率42.2W,傳熱量減少逾50%;在攪拌頭旋轉速度800 r/min,焊接速度200 mm/min的情況下,使用常規(guī)攪拌頭焊接焊核區(qū)最高溫度約430℃,使用隔熱攪拌頭焊核區(qū)最高溫度約460℃,溫度提升30℃左右,使用常規(guī)攪拌頭向上傳熱功率84.8W,使用隔熱攪拌頭向上傳熱功率43.3W,此時常規(guī)攪拌頭焊接熱效率為92.2%,隔熱攪拌頭熱效率為96.0%,熱效率提升3.8%。本文還通過有限元模擬對將隔熱攪拌頭設計用于鋼材焊接時可能產生的效果做了初步探討,模擬結果認為攪拌頭隔熱可使鋼材攪拌摩擦焊主軸溫度大幅下降,使其焊接熱效率得到顯著提升。
[Abstract]:Friction stir welding (FSW) is a kind of solid phase welding technology in which the welding material is not melted. It has the advantages of high energy utilization, no harmful gas and no waste in the welding process. It is especially suitable for welding metals with low hardness and melting point such as aluminum alloy, magnesium alloy, etc. At present, the research on friction stir welding mainly focuses on the optimization design of welding process parameters and the design of stir head. Material flow mechanism, heat generation mechanism, In this paper, the heat transfer of the friction stir welding head to the main axis is studied by means of the combination of experiments and computer simulation, and the heat insulation friction stir welding stir head is designed and manufactured. The heat transfer from the mixing head to the spindle is reduced, the temperature of the spindle is reduced, and the heat loss during welding is reduced, and the welding heat efficiency is improved. In this paper, a new type of mixing head structure is designed with the help of finite element numerical simulation, which is helpful to reduce heat transfer. Plasma spraying method was used to spray Y _ 2O _ 3 stabilized ZrO _ 2 thermal barrier coating on the clamping handle of mixing head to reduce heat transfer in the direction of main axis. The welding experiments of 6061-T6 aluminum alloy plate with 5mm thickness were carried out by using the conventional mixer and the heat insulation mixer designed by our institute. The temperature field of the mixing head, the spindle of the machine tool and the welding test plate during the welding process were measured. The heat insulation effect of the heat insulation mixer was studied and the welding heat efficiency was calculated. The experimental results show that the highest steady state temperature of the outer surface of the spindle welded by conventional mixing head is 82.8 鈩，

本文編號：1631496