AlMgSiCu合金大应变轧制及力学行为研究

发布时间：2018-05-01 07:31

本文选题：AlMgSiCu合金 + 轧制工艺　；参考：《广西科技大学》2017年硕士论文

【摘要】：AlMgSiCu合金具有中等强度、密度低、良好的耐腐蚀性、焊接性、成形性等优点。在航空、汽车、轨道运输、建筑等领域得到了广泛的应用。为改善合金力学性能,使得其得到了增强,同时在减振降噪技术中选择经济、有效和方便的途径,从而提高产品的安全性和寿命。针对这需求,本论文在AlMgSiCu合金基础上,结合实际生产及检验条件,通过分析不同热处理工艺、轧制工艺、合金元素等对板材力学性能及阻尼特性的影响,探索合金显微组织、力学性能及阻尼特性的影响规律,从而优化工艺参数,为实际生产提供指导意义。本次研究得到的结论及规律如下:(1)采用均匀化处理消除铸态枝晶偏析。合金经560℃×24h均匀化处理,组织中非平衡相基本溶解,晶粒得到明显细化,硬度值达到最高,抗拉强度为204 MPa,屈服强度为187 MPa,伸长率达8.5%。(2)对AlMgSiCu合金进行大应变轧制试验,据研究,影响轧制工艺的有轧制速率,道次变形量及轧制温度等,通过对以上三种因素进一步探索,得出AlMgSiCu合金在经过400℃、10s-1应变速率热轧和固溶时效后,合金性能明显提高,此时的硬度值到达103.3HV,抗拉强度到达350MPa,伸长率到达35.5%。(3)合理优化主要合金元素含量以及适量调整加入微量元素含量的比例可以有效地提高强化效果,改善AlMgSiCu合金的组织及力学性能。为提高合金力学性能,AlMgSiCu合金的抗拉强度随Zr含量的增加而增加,0.7%Zr时抗拉强度高达490MPa;适当增加Er、Mn元素质量分数的增加,合金力学性能显著提高,0.7%Mn时抗拉强度到达493MPa;Zr、Mn元素更能显著的改善AlMgSiCu合金组织及力学性能。(4)通过模量和阻尼值的确定判断合金的减声降噪性能。不同工艺下阻尼值均有差异,寻找规律,总体来说,轧制态下,阻尼值更易出现峰值,弹性模量易出现最低值。不同轧制速率变形后合金内形成了大量的位错,可动位错密度相差较大,对AlMgSiCu合金性能影响差别更明显。热处理过后,轧制速率对AlMgSiCu铝合金的阻尼特性具有相同的规律,弹性模量随着温度的增加呈线性关系下降,在室温和高温下,频率对合金阻尼的作用不同。
[Abstract]:AlMgSiCu alloy has the advantages of medium strength, low density, good corrosion resistance, weldability, formability and so on. It has been widely used in the fields of aviation, automobile, rail transportation, building and so on. In order to improve the mechanical properties of the alloy, it has been enhanced, and the method of selecting economy, effective and convenient in vibration reduction and noise reduction technology is improved. On the basis of this demand, on the basis of AlMgSiCu alloy, the influence of different heat treatment process, rolling process and alloy element on the mechanical properties and damping characteristics of plate is analyzed on the basis of the actual production and inspection conditions, and the influence rules of the alloy microfabric, mechanical properties and damping characteristics are explored. The conclusions and rules obtained in this study are as follows: (1) using homogenization treatment to eliminate the cast dendrite segregation. After the homogenization of the alloy at 560 C 24h, the nonequilibrium phase in the microstructure is basically dissolved, the grain is refined, the hardness is the highest, the tensile strength is 204 MPa, and the yield strength is 18. 7 MPa, the elongation rate of 8.5%. (2) has been tested for large strain rolling of AlMgSiCu alloy. According to the study, the rolling rate, the amount of pass deformation and the rolling temperature are affected. Through the further exploration of the above three factors, it is concluded that the properties of the AlMgSiCu alloy are obviously improved after the 10s-1 strain rate hot rolling and the solid solution aging. At this time, the hardness value reaches 103.3HV, the tensile strength reaches 350MPa, the elongation reaches to 35.5%. (3) and the rational optimization of the main alloy element content and the proportion of adding trace element content can effectively improve the strengthening effect and improve the microstructure and mechanical properties of the AlMgSiCu alloy. In order to improve the mechanical properties of the alloy, the tensile strength of the AlMgSiCu alloy is improved. The strength increases with the increase of Zr content, the tensile strength is up to 490MPa at 0.7%Zr, the increase of Er, the increase of the mass fraction of Mn elements, the increase of the mechanical properties of the alloy, the tensile strength of 0.7%Mn to 493MPa, Zr, and Mn elements can significantly improve the microstructure and mechanical properties of AlMgSiCu alloy. (4) judging the alloy by the determination of modulus and damping value. Noise reduction and noise reduction performance. Under different processes, the damping values are different. In general, the damping value is easier to appear in the rolling state, and the modulus of elasticity is easy to have the lowest value. A large number of dislocations are formed in the alloy after the deformation of different rolling rates. The difference of the movable dislocation density is larger, and the difference in the performance of AlMgSiCu alloy is more obvious. After that, the rolling rate has the same law on the damping characteristic of AlMgSiCu aluminum alloy, and the elastic modulus decreases linearly with the increase of temperature. At room temperature and high temperature, the effect of frequency on alloy damping is different.

【学位授予单位】：广西科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG339

【参考文献】