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  本文選題：慣性徑向摩擦焊　切入點：7A04鋁合金　出處：《重慶大學(xué)》2015年碩士論文

【摘要】：鋁銅金屬材料在工業(yè)生產(chǎn)中的應(yīng)用越來越廣泛,然而由于兩種材料的化學(xué)成分、機械性能及熔點的差異,鋁-銅異種金屬的焊接一直是材料學(xué)科中的難點。慣性徑向摩擦焊接是利用摩擦產(chǎn)熱來實現(xiàn)材料的固相連接技術(shù),對于異種金屬材料的焊接有壓倒性的優(yōu)勢。因此,本文針對7A04鋁棒和T2紫銅環(huán)異種金屬材料,采用慣性徑向摩擦焊接方法探索性的對其可行性進(jìn)行研究。然而,目前關(guān)于鋁-銅異種金屬材料摩擦焊接的相關(guān)研究較少。本文通過實驗的方法,對實驗所得摩擦焊接頭的宏觀形貌進(jìn)行分析,利用光學(xué)顯微鏡和掃描電鏡對接頭微觀組織進(jìn)行觀察,對接頭的顯微硬度和剪切強度進(jìn)行測試。分析結(jié)果表明:采用慣性徑向摩擦焊接方法來焊接7A04鋁和T2紫銅異種金屬材料是可行的。當(dāng)最高轉(zhuǎn)速為4100r/min,預(yù)摩擦轉(zhuǎn)速和摩擦轉(zhuǎn)速為4000r/min,頂鍛轉(zhuǎn)速為2000r/min,頂鍛壓力和摩擦壓力分別為8.0MPa和4.0MPa時,接頭質(zhì)量最穩(wěn)定且最佳,接頭界面產(chǎn)生塑性變形層、動態(tài)再結(jié)晶、元素擴散互溶,實現(xiàn)了冶金結(jié)合。接頭焊縫包含3個區(qū)域:細(xì)晶粒區(qū)(Ⅰ區(qū),FGZ)、過渡區(qū)(Ⅱ區(qū),TZ)及熱影響區(qū)(Ⅲ區(qū),HAZ);FGZ和HAZ為圓形顆粒狀晶粒,FGZ晶粒尺寸細(xì)小,HAZ晶粒粗大,大于母材;TZ晶粒呈細(xì)長狀,尺寸大小不一,平均晶粒尺寸介于細(xì)晶粒區(qū)和母材區(qū)之間。顯微硬度和剪切強度測試結(jié)果與宏觀和微觀分析結(jié)果吻合。本文還對摩擦焊中飛邊形成機理進(jìn)行了分析,提出了飛邊效應(yīng),并分析了工藝參數(shù)對接頭質(zhì)量的影響規(guī)律。結(jié)果發(fā)現(xiàn),飛邊形成機理就是在徑向力的切向分力與摩擦力的合力作用下,導(dǎo)致材料向合力方向流動,并且合力越大的地方流動速度及材料流動量越大,從而形成飛邊。焊接之前必須除去鋁材表面的氧化膜,文中以產(chǎn)生飛邊的形式將其擠出,飛邊多少的表現(xiàn)形式為燒損量的大小,本文中最佳燒損量值范圍:3.0-3.5mm之間。頂鍛壓力和摩擦壓力對燒損量大小起著決定性的作用;摩擦壓力與燒損量呈正相關(guān)關(guān)系,即摩擦壓力越大,燒損越高;摩擦壓力越小,燒損越低。摩擦壓力對焊接接頭質(zhì)量有很大影響,在摩擦壓力值大于4MPa時,形成的焊接接頭質(zhì)量更良好,不易形成缺陷。
[Abstract]:Aluminum-copper metal materials are widely used in industrial production. However, due to the difference of chemical composition, mechanical properties and melting point of the two materials, the welding of Al-Cu dissimilar metals is always a difficult point in the field of materials.Inertial radial friction welding (IRFW) is a solid phase bonding technology which uses friction heat to realize material bonding. It has an overwhelming advantage for dissimilar metal welding.Therefore, the feasibility of inertial radial friction welding (IRFW) for 7A04 aluminum rod and T2 copper ring dissimilar metal materials is studied in this paper.However, there are few researches on friction welding of aluminum-copper dissimilar metal materials.In this paper, the macroscopic morphology of friction welded joints was analyzed by means of experiments. The microstructure of the joints was observed by optical microscope and scanning electron microscope, and the microhardness and shear strength of the joints were tested.The results show that it is feasible to weld 7A04 aluminum and T2 copper dissimilar metals by inertial radial friction welding.When the maximum rotational speed is 4100r / min, the prefriction speed and friction speed are 4000r / min, the forging speed is 2000rr / min, the forging pressure and friction pressure are 8.0MPa and 4.0MPa, respectively, the quality of the joint is the most stable and the best, the plastic deformation layer is produced at the interface of the joint, and the dynamic recrystallization occurs.The element diffuses and dissolves mutually, realizes the metallurgical union.The average grain size is between the fine grain area and the base metal region.The results of microhardness and shear strength are in agreement with the results of macro and micro analysis.In this paper, the mechanism of flash edge formation in friction welding is analyzed, the flash effect is put forward, and the influence of process parameters on joint quality is analyzed.The results show that the mechanism of flange formation is caused by the combined force of tangential force and friction force of radial force, resulting in the flow of materials towards the direction of resultant force, and the greater the resultant force, the greater the velocity of flow and material flow, thus forming the flying edge.Before welding, the oxide film on the aluminum surface must be removed, and extruded in the form of flash edge in this paper. The form of flash edge is the size of burning loss. The optimum burning loss value in this paper is between 3. 0 and 3. 5 mm.The forging pressure and friction pressure play a decisive role in the burning loss, and the friction pressure has a positive correlation with the loss amount, that is, the higher the friction pressure, the higher the burning loss, and the lower the friction pressure, the lower the burn loss.The friction pressure has a great influence on the quality of welded joints. When the friction pressure is greater than 4MPa, the quality of welded joints is better and the defects are not easy to be formed.
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG453.9

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 馮健;7A04鋁合金/304不銹鋼摩擦焊接工藝及焊后熱處理研究[D];西南交通大學(xué);2017年

2 羅添元;鈦合金與銅、鋼異種金屬焊接性研究[D];南京理工大學(xué);2017年

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本文編號：1704075