2024铝合金半固态模锻组织均匀性研究
发布时间：2019-04-25 16:49
【摘要】：我国的交通运输业以及武器装备业的现代化、高速化是主要发展方向,轻量化要求日趋强烈,特别是轻量化要求高的飞机、航天器、高速列车、货运车、汽车、火炮、坦克以及机械设备等重要受力部件和结构件等,大量使用铝合金锻件和模锻件来代替原来的钢结构件。普通的铝合金生产方法以及传统的模锻技术难以满足关键零部件的制造需求和使用性能,由于这种需求的客观存在,使得半固态模锻技术得到广泛的关注。本文采用计算机模拟和实验相结合的方法,研究了半固态模锻工艺参数对2024合金组织均匀性的影响。采用水淬法制备试样,用定量金相的方法研究了半固态2024合金初生固相率与温度的关系,绘制了初生固相率与温度的关系曲线。应用DEFORM-3D软件对2024铝合金半固态模锻充型过程以及速度场进行了模拟,研究了不同模锻工艺参数下2024铝合金杯形件充型过程和半固态浆料的流动特点。研究表明:坯料温度越高,充型越不平稳,速度场越不均匀;压头温度越高,充型越平稳,速度场越均匀。在模拟的基础上,采用实验的方法研究了半固态模锻工艺参数对2024铝合金杯形件组织均匀性的影响,研究结果表明:半固态模锻2024合金杯形件的液相偏析度随着合金温度的增加而增加、随着模具压头温度的升高而减少、随着保压时间的延长而减少、随着充型速度的提高而增加。本实验条件下,在合金温度为626℃、模具压头温度为409℃、保持时间为4s、充型速度为3.5mm/s的工艺参数下,半固态模锻2024铝合金杯形件液相偏析度最小并且成形性较好。压头温度过低会导致在杯形件杯口处出现充型不足的缺陷;在液相与固相交接处,由于两相组织的收缩率不同易出现缩孔缩松应力集中裂纹等显微缺陷。
[Abstract]:The modernization of transportation industry and weapon equipment industry in our country, the high speed is the main development direction, the demand for lightweight is becoming stronger and stronger, especially for the aircraft, spacecraft, high-speed train, freight car, automobile and artillery, especially for the aircraft, spacecraft, high-speed train, freight car, automobile, artillery, and so on. Aluminum alloy forgings and die forgings are widely used in tank and mechanical equipment to replace the original steel structures. The common aluminum alloy production method and the traditional die forging technology can not meet the manufacturing demand and performance of key parts. Because of the objective existence of this demand, semi-solid die forging technology has been paid more and more attention. In this paper, the effect of semi-solid die forging parameters on microstructure uniformity of 2024 alloy was studied by means of computer simulation and experiment. The relationship between primary solid rate and temperature of semi-solid 2024 alloy was studied by means of quantitative metallography, and the relationship curve between primary solid rate and temperature was drawn. The filling process and velocity field of 2024 aluminum alloy semi-solid die forging were simulated by DEFORM-3D software. The filling process of 2024 aluminum alloy cup-shaped parts and the flow characteristics of semi-solid slurry under different die forging parameters were studied. The results show that the higher the billet temperature is, the more non-stationary the filling is, the more uneven the velocity field is, the higher the head temperature is, the more stable the filling is, and the more uniform the velocity field is. On the basis of simulation, the influence of semi-solid die forging process parameters on the microstructure uniformity of cup-shaped parts of 2024 aluminum alloy was studied experimentally. The results show that the liquid phase segregation of 2024 alloy cup-shaped parts in semi-solid die forging increases with the increase of alloy temperature, decreases with the increase of die head temperature, and decreases with the prolongation of holding time. With the increase of mold filling speed. Under the conditions of alloy temperature of 626 鈩，
本文编号：2465295
[Abstract]:The modernization of transportation industry and weapon equipment industry in our country, the high speed is the main development direction, the demand for lightweight is becoming stronger and stronger, especially for the aircraft, spacecraft, high-speed train, freight car, automobile and artillery, especially for the aircraft, spacecraft, high-speed train, freight car, automobile, artillery, and so on. Aluminum alloy forgings and die forgings are widely used in tank and mechanical equipment to replace the original steel structures. The common aluminum alloy production method and the traditional die forging technology can not meet the manufacturing demand and performance of key parts. Because of the objective existence of this demand, semi-solid die forging technology has been paid more and more attention. In this paper, the effect of semi-solid die forging parameters on microstructure uniformity of 2024 alloy was studied by means of computer simulation and experiment. The relationship between primary solid rate and temperature of semi-solid 2024 alloy was studied by means of quantitative metallography, and the relationship curve between primary solid rate and temperature was drawn. The filling process and velocity field of 2024 aluminum alloy semi-solid die forging were simulated by DEFORM-3D software. The filling process of 2024 aluminum alloy cup-shaped parts and the flow characteristics of semi-solid slurry under different die forging parameters were studied. The results show that the higher the billet temperature is, the more non-stationary the filling is, the more uneven the velocity field is, the higher the head temperature is, the more stable the filling is, and the more uniform the velocity field is. On the basis of simulation, the influence of semi-solid die forging process parameters on the microstructure uniformity of cup-shaped parts of 2024 aluminum alloy was studied experimentally. The results show that the liquid phase segregation of 2024 alloy cup-shaped parts in semi-solid die forging increases with the increase of alloy temperature, decreases with the increase of die head temperature, and decreases with the prolongation of holding time. With the increase of mold filling speed. Under the conditions of alloy temperature of 626 鈩，
本文编号：2465295
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