本文選題：高硅鋁合金　切入點(diǎn)：攪拌摩擦加工　出處：《合肥工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：高鋁硅合金具有比重小、導(dǎo)熱性好、耐磨耐蝕性好、強(qiáng)度高、硬度大以及易回收等優(yōu)點(diǎn),被廣泛地應(yīng)用于汽車、飛機(jī)、坦克及船用發(fā)動機(jī)等工業(yè)部門中。但是高硅鋁合金常用的制備方法各有優(yōu)缺點(diǎn),限制了高硅鋁合金材料的制備及應(yīng)用。因此選擇合適的制備工藝,以得到顆粒細(xì)小、分布均勻、尖端和棱角較少的高硅鋁合金成為了高硅鋁合金制備工藝的研究方向。攪拌摩擦加工技術(shù)(FSP)利用攪拌頭所造成加工區(qū)材料的劇烈塑性變形、混合、破碎和熱暴露,可以實(shí)現(xiàn)微觀結(jié)構(gòu)的致密化、均勻化和細(xì)化。攪拌摩擦加工技術(shù)一方面可以用來制備鋁硅合金材料,另一方面也可以用來消除有缺陷鑄造鋁硅合金中的缺陷。本文在研究高硅鋁合金性能及常用制備方法的基礎(chǔ)上,利用自主設(shè)計(jì)的攪拌工具及工裝夾具,采用攪拌摩擦加工添加硅顆粒法和鑄造加攪拌摩擦加工法制備高硅鋁合金材料。結(jié)果表明:選擇錐臺帶螺紋型攪拌針,攪拌摩擦加工添加硅顆粒法和鑄造加攪拌摩擦加工法均可以制備得到硅顆粒分布均勻、無缺陷的高鋁硅合金材料。最佳的工藝參數(shù)為攪拌針旋轉(zhuǎn)速度為950 rpm、進(jìn)給速度為47.5mm/min、交替更改攪拌方向攪拌4道次。但是攪拌摩擦加工添加硅顆粒法制備得到的高硅鋁合金中硅含量僅僅能達(dá)到14.2%,不能滿足試驗(yàn)及使用要求。對采用鑄造加攪拌摩擦加工法制備得到的Al-40Si材料進(jìn)行組織及性能分析。鑄造加攪拌摩擦加工后硅顆粒得到了顯著地細(xì)化,硅顆粒平均直徑在3μm左右;硬度值由鑄造母材的70 HV提高到了120 HV左右,提升了60%左右;拉伸強(qiáng)度由鑄造母材的50 MPa左右提高到了接近于270 MPa,幾乎達(dá)到了母材拉伸強(qiáng)度的5倍;在摩擦磨損試驗(yàn)中,攪拌后材料的磨損量幾乎不隨著加載力的增加而增加,高硅鋁合金的耐磨性得到了顯著地改善。
[Abstract]:High Al-Si alloy has the advantages of small specific gravity, good thermal conductivity, good wear and corrosion resistance, high strength, high hardness and easy to be recovered, so it is widely used in automobile, aircraft, etc. In the industrial sectors such as tank and marine engine, however, the common preparation methods of high silicon aluminum alloy have their own advantages and disadvantages, which limit the preparation and application of high silicon aluminum alloy materials. High silicon aluminum alloy with low edge and low angle has become the research direction of preparation technology of high silicon aluminum alloy. FSPS (friction stir processing technology) makes use of the stirring head to cause severe plastic deformation, mixing, crushing and thermal exposure of the materials in the processing zone. It can realize the densification, homogenization and refinement of microstructure. Friction stir processing technology can be used to prepare Al-Si alloy materials on the one hand, On the other hand, it can also be used to eliminate the defects in Al-Si alloy. On the basis of studying the properties and common preparation methods of high-silicon aluminum alloy, this paper makes use of the self-designed mixing tool and fixture. High silicon aluminum alloy materials were prepared by friction stir processing by adding silicon particle method and by casting and friction stirring process. The results show that the taper table with thread type stirring needle is selected. The distribution of silicon particles can be obtained by adding silicon particles in friction stir processing and casting with friction stir processing. The optimum technological parameters are as follows: the rotating speed of the stirring needle is 950 rpm, the feed speed is 47.5 mm / min, and the stirring direction is changed alternately for 4 passes. However, the friction stirring process with the addition of silicon particle method is high. The content of silicon in silicon aluminum alloy can only reach 14.2, which can not meet the requirements of test and application. The microstructure and properties of Al-40Si prepared by casting and friction stir processing are analyzed. The silicon particles after casting and friction stir processing are analyzed. We get a significant refinement, The average diameter of silicon particles is about 3 渭 m, the hardness is increased from 70 HV to 120HV, and the tensile strength is increased from 50 MPa to nearly 270MPa, which is almost 5 times of the tensile strength of the base metal. In the friction and wear test, the wear resistance of high silicon aluminum alloy was improved significantly with the increase of loading force.
【學(xué)位授予單位】：合肥工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG146.21

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1 盛桂林;;高硅鋁合金腐蝕評論[J];輕合金加工技術(shù);1975年04期

2 王湘君;;高硅鋁合金中銻、銅、錳、鎂、鐵的原子吸收分光光度法測定[J];湖南冶金;1977年04期

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本文編號：1628882