發(fā)布時間：2018-05-15 11:56

  本文選題：攪拌摩擦焊 + 工藝優(yōu)化��； 參考：《蘭州理工大學(xué)》2016年碩士論文

【摘要】：由于現(xiàn)代經(jīng)濟嚴重依賴于石化能源的消耗,因此導(dǎo)致能源供應(yīng)日趨緊張、環(huán)境壓力加劇。經(jīng)濟社會的發(fā)展要求節(jié)能減排,而汽車輕量化是我國節(jié)能減排戰(zhàn)略環(huán)節(jié)中較為重要的一部分,其中輕量化應(yīng)用新材料包括鋁合金、鎂合金、鈦合金、高性能塑料、多孔發(fā)泡及復(fù)合材料等。攪拌摩擦焊對于焊接材料適用范圍廣泛,同時也能夠焊接物理性能差異巨大的異種材料。因此,本文將攪拌摩擦焊技術(shù)應(yīng)用于ABS高分子塑料的焊接、ABS與鋁合金的焊接。工藝試驗結(jié)果表明,攪拌摩擦焊可以實現(xiàn)非金屬塑料ABS、ABS與6082鋁合金的焊接。為了驗證攪拌摩擦焊對非金屬塑料的焊接適用性,采用攪拌摩擦焊技術(shù)焊接ABS塑料。工藝試驗結(jié)果表明當(dāng)轉(zhuǎn)速為1300r/min、下壓量為0.15mm、焊接速度為20mm/min,可以實現(xiàn)ABS對焊的有效連接。接頭強度可達到20.5MPa,達到母材的68%,焊縫前進側(cè)與后退側(cè)表面形態(tài)趨近一致,表面無明顯的毛刺與未融合白化現(xiàn)象。采用攪拌摩擦搭接點焊焊接ABS塑料,工藝參數(shù)對接頭力學(xué)性能影響因素主次為:停留時間轉(zhuǎn)速下壓量。上、下板結(jié)合面處,斷面較為平整,分子鏈端實現(xiàn)了有效的融合與交聯(lián)。焊點出現(xiàn)分層現(xiàn)象并且斷裂始于混合分層和上、下板材結(jié)合面處。采用攪拌摩擦點焊焊接ABS與鋁合金時,攪拌頭是否有攪拌針對點焊連接的影響區(qū)別較大。焊后焊點表面均較為平整,成形美觀,可以實現(xiàn)6082與ABS可靠連接。但是在不同焊接工藝下最優(yōu)焊接參數(shù)不同,且抗拉剪載荷差距明顯。這是由于無攪拌針焊接接頭最高溫度比有針焊接拌頭溫度高100℃,因此無匙孔焊接接頭連接面積大于后者,最終使得前者接頭強度高于后者。對比接頭斷裂位置發(fā)現(xiàn),接頭均斷裂與ABS一側(cè)。以最優(yōu)焊接參數(shù)焊接時,接頭出現(xiàn)兩種斷裂模式:剝離斷裂和ABS母材塑性斷裂,其中ABS母材塑性斷裂包括,沿著焊點結(jié)合面向兩端擴展斷裂,沿焊點邊緣位置沿直線線外擴展斷裂兩種形式。接頭斷裂經(jīng)歷了3個階段:裂紋萌生、穩(wěn)定擴展、快速擴展,在拉剪破壞過程中形成了有明顯區(qū)別的裂紋擴展花樣,第三階段在斷面上裂紋擴展速度最快。點焊斷裂破壞起源于鋁合金和ABS軸間邊緣結(jié)合界面的氣泡缺陷與微裂紋。點焊接頭的結(jié)合力來自于兩種材料接觸界面的分子力與機械結(jié)合力包括,ABS分子與鋁合金表面、Al2O3氧化物在摩擦熱的作用下發(fā)生交聯(lián)固化,形成分子間結(jié)合力;樹脂分子鏈端與鋁合金鋁原子、表面氧化物互相在另一材料基體上“釘扎”獲得的機械結(jié)合力。
[Abstract]:Because the modern economy depends heavily on the consumption of fossil energy, the energy supply becomes increasingly tight and environmental pressure intensifies. The development of economy and society requires energy saving and emission reduction. Automobile lightweight is an important part of the strategy of energy saving and emission reduction in China. The new materials of lightweight application include aluminum alloy, magnesium alloy, titanium alloy, high performance plastics, etc. Porous foaming and composite materials. Friction stir welding (FSW) is widely used for welding materials, and it can also be used to weld dissimilar materials with great difference in physical properties. Therefore, friction stir welding (FSW) technology is applied to the welding of ABS polymer plastics and aluminum alloy. The experimental results show that friction stir welding can realize the welding of non-metallic plastics ABSS-ABS and 6082 aluminum alloy. In order to verify the applicability of friction stir welding (FSW) to non-metallic plastics, friction stir welding (FSW) was used to weld ABS plastics. The experimental results show that the ABS butt welding can be realized effectively when the rotational speed is 1300 r / min, the lower pressure is 0.15 mm and the welding speed is 20 mm / min. The strength of the joint is up to 20.5 MPa, and the weld metal is 68. The surface morphology of the forward and backward sides of the weld seam is close to the same, and there is no obvious burr and no whitening on the surface. Friction stir spot welding (FSW) was used to weld ABS plastics. The main and secondary factors affecting the mechanical properties of the joints were as follows: the pressure under the residence time and rotational speed. The cross section of the upper and lower plate is smooth, and the molecular chain end can be effectively fused and crosslinked. The solder joint appears delamination and fracture begins with mixed delamination and upper and lower plate bonding. When friction stir spot welding (FSW) is used to weld ABS and aluminum alloy, the effect of stir head on spot welding joint is different. After welding, the surface of solder joint is flat and the shape is beautiful. 6082 and ABS can be connected reliably. However, the optimal welding parameters are different in different welding processes, and the difference between tensile and shear loads is obvious. This is due to the fact that the maximum temperature of the welded joint without stirring needle is 100 鈩，

本文編號：1892371