共查询到20条相似文献,搜索用时 31 毫秒
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A6111 is an aluminum alloy, which exhibits good formability and excellent bake hardening property. This study aimed to reveal the influence of strain path, pre-strain orientation(α) as well as pre-strain level on the mechanical properties of A6111-T4 P sheet under bake treatment through uniaxial tension test.(0–5)% pre-strain, 150–170 °C bake temperature and 20–30 min bake time were considered in the study by referring to the actual production process. The results show that both pre-strain level and strain path play significant roles in improving the material properties. In the condition that tensile orientation(β) parallel with pre-strain orientation(β = α), the yield strength can be remarkably improved, and much higher parameter of n in Hockett–Sherby model can be obtained than those when tensile orientation non-parallel with pre-strain orientation(α≠β). In addition, when the pre-strain level, paint bake process were settled and β = α, the curves obtained in five tension orientations are similar in the plastic deformation stage. 相似文献
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2A12—T81铝合金板材热处理工艺研究 总被引:2,自引:0,他引:2
研究了固溶热处理及人工时效工艺对2A12-T81铝合金板材的组织与性能的影响规律,指出了适用于100℃或更高温度下工作的板材的热处理工艺参数。 相似文献
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对高强度铝合金7075-T6在0.03s-1应变率下,50~250℃温度范围进行系列单向拉伸试验,并测得不同温度下的厚向异性系数R。结果表明:7075-T6铝合金的流动应力随试验温度的升高而减小;在50~200℃温度区间,延伸率随温度的升高而增加;当温度为250℃时,由于T6特性的消失,延伸率反有所降低,得到最佳的成形温度在200℃左右;并且通过对3种不同屈服函数Mises,Hill48和Barlat89比较,得到能准确方便描述7075-T6各向异性的屈服函数,确定了不同温度下屈服函数的参数。 相似文献
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系统改变A201铝合金平板铸件的长度、厚度及冒口尺寸,以探讨不同铸造条件下,A201平板铸件相对位置的力学性能与X射线检测结果之间的关系,可为冒口设计及金属凝固提供参考.型砂为100%硅砂.试验结果表明,A201铝合金平板铸件的力学强度与X射线照相试片等级不存在绝对的对应关系. 相似文献
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P. J. Zhao Z. H. Chen C. F. Dong 《Journal of Materials Engineering and Performance》2014,23(11):4032-4041
Based on the frame work of continuum damage mechanics, a research work of anisotropic damage evolution in warm stamping process of magnesium alloy sheets has been carried out by means of a combined experimental-numerical method. The aim was to predict formability of warm stamping of AZ31 Mg alloy sheets by taking the thermal and damage effects into account. In the presented work, a temperature-dependent anisotropic yield function suitable for cold rolling sheet metals together with an anisotropic damage model was implemented into the a VUMAT subroutine for ABAQUS/EXPLICIT. The evolution of internal damage in the form of void growth and coalescence in AZ31 Mg alloy sheet was observed by means of scanning electron microscopy (SEM). Moreover, a coupled thermo-mechanical simulation of the stamping process was performed using the implemented code at different temperatures. The parameters employed in the simulation were determined by the standard tensile tests and algebraic manipulation. The overall anisotropic damage process from crack initiation to final propagation in local area of blank was simulated. Numerical results show that the prediction of the site of crack initiation and the orientation of crack propagation are consistent with the data observed in warm stamping experiments. 相似文献
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含有不同尺度微裂纹的铝合金伸长率模型 总被引:2,自引:0,他引:2
基于铝合金在变形过程中形成不同尺度的微裂纹,建立了铝合金伸长率与微米级的结晶相及沿晶界分布的亚微米级的弥散相的非线性解析模型,模型的预测与试验值较为符合。借助模型的理论分析,可以定量地得出不同尺度的结晶相,弥散相含量及尺寸对铝合金伸长率的影响。同时,根据模型的解析结果,提出了改善铝合金伸长率的方法。 相似文献
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Louis G. HectorJr. Yen-Lung Chen Sumit Agarwal Clyde L. Briant 《Journal of Materials Engineering and Performance》2007,16(4):404-417
In this second part, a state-of-the-art digital image correlation (DIC) technique was used to compute true stress-true strain
curves beyond diffuse necking for friction stir processed AA5182-O and AA6111-T4 aluminum alloys. Of particular interest were
differences in key tensile properties, such as initial yield point, and ultimate tensile strength, between the base and friction
stir processed materials. Tensile coupons cut from the same material used to investigate crystallographic texture via the
electron backscatter diffraction technique in Part 1, were strained to failure in a miniature tensile stage. The evolution
of two-dimensional strain fields in both the base and friction stir processed materials was explored with incremental and
cumulative strain maps computed from digital grids superimposed on each image after testing was completed. The impact of friction
stir processing on strain localization just prior to fracture was revealed through changes in incremental strain map contour
profiles. It is suggested that grain size refinement due to friction stir processing has a prominent effect on strength, while
texture plays a secondary role.
This article was presented at Materials Science & Technology 2006, Innovations in Metal Forming symposium held in Cincinnati,
OH, October 15-19, 2006. 相似文献
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铝合金板温成形过程中凸凹模圆角处摩擦的测量 总被引:3,自引:0,他引:3
在温成形过程中铝合金板与模具表面的接触和摩擦行为十分复杂,不同的接触区域摩擦状况不尽相同。本文分析了板料成形中摩擦测量的国内外发展状况,采用自行设计的新型摩擦测量装置完成了铝合金板温成形过程中凸凹模圆角处摩擦系数的测量。该测量装置的特点是可以模拟板料的真实变形过程,因而可以获得更为准确的测量结果。 相似文献
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Jianguang Liu Zhongjin Wang Qingyuan Meng 《Journal of Materials Engineering and Performance》2012,21(4):429-436
Lightweight materials have been widely used in aerospace, automobile industries to meet the requirement of structural weight
reduction. Due to their limited plasticity at room temperature, however, lightweight materials always exhibit distinctly poor
forming capability in comparison with conventional deep drawing steels. Based on the phenomenon that the superimposed hydrostatic
pressure can improve the plasticity of metal, many kinds of double-sided pressure forming processes have been proposed. In
the present study, the Gurson-Tvergaard-Needleman (GTN) damage model combined with finite element method is used to investigate
the influence of double-sided pressure on the deformation behavior of biaxially stretched AA6111-T4 sheet metal, including
nucleation and growth of microvoids, evaluation of stress triaxiality, and so forth. The Marciniak-Kuczynski (M-K) localized
necking model is used to predict the right-hand side of the forming limit diagram (FLD) of sheet metal under superimposed
double-sided pressure. It is found that the superimposed double-sided pressure has no obvious effect on the nucleation of
microvoids. However, the superimposed double-sided pressure can suppress the growth and coalescence of microvoids. The forming
limit curve (FLC) of the biaxially stretched AA6111-T4 sheet metal under the superimposed double-sided pressure is improved
and the fracture locus shifts to the left. Furthermore, the formability increase value is sensitive to the strain path. 相似文献
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文主要是研究温轧对双辊铸轧6061铝合金板材进行处理,观察不同温轧温度及累积压下量对铸轧板材的影响。采用光学显微镜(OM),扫描电镜(SEM),X射线衍射仪(XRD),显微硬度仪和万能拉伸机等设备,观察了铸轧板材及温轧板材的显微组织,获得了材料的硬度、强度和延伸率等力学性能。研究表明,铸轧6061合金中主要含有耐热相Al0.7Fe3Si0.3、Al9Fe0.84Mn2.16Si及少量强化相Mg2Si。合金中第二相随温轧道次的递增逐渐由网格状、片状转变为沿轧制方向的线条状,最终变为细小的颗粒状。经过温轧后,产生新的析出相Al0.5Fe3Si0.5且Mg2Si析出相增多。铸轧板材温轧后,硬度随压下量的增大呈线性递增,且当温轧温度为370℃时,硬度曲线斜率最大为2.42114。此时细小的AlFeSi类析出相及Mg2Si强化相均匀弥散分布于合金中,板材的硬度最大,可达84.28 HV,抗拉强度、屈服强度和延伸率分别为209.34 MPa、79.09 MPa和20.11%。 相似文献
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分别在空气和循环水冷条件下对2024-T4铝合金板进行搅拌摩擦焊接(friction stir welding,FSW),研究了水冷介质对FSW接头组织性能的影响.结果表明:循环水冷介质具有明显的瞬时快冷作用,水冷介质下FSW可以显著细化晶粒,并抑制焊核区析出相的生长,焊核区的平均晶粒尺寸达到700 nm,析出相尺寸达到30~200 nm.水冷介质减弱了FSW接头的热软化效应,改善了接头的组织和性能,使焊核区HV显微硬度值提高了234 MPa,接头抗拉强度提高了52.2 MPa,但试样延伸率有所下降. 相似文献
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基于板料成形时法兰区周向收缩、厚向增厚的特点和温成形的环境,针对铝合金板温成形过程拉深筋部位摩擦系数的测量,研制了一套新型摩擦测试装置.探讨了压边力、成形温度、润滑状态三种工艺参数和铝合金板试样楔形角对拉深筋部位摩擦系数的影响.研究表明,成形温度和润滑剂对摩擦系数影响比压边力明显;当不采用润滑剂时,随着成形温度从室温上升到250℃,摩擦系数有明显的增加;在高温状态下,三种润滑剂的使用,都可以大大降低温成形时的摩擦系数,但这三种润滑剂之间的润滑效果差异并不明显;在不同楔形角的铝合金试样成形过程中,拉深筋部位的摩擦系数随着角度的增大而增大. 相似文献
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针对飞机用7050高强铝合金含孔板件进行拉伸性能与断裂韧性的模拟分析与实验研究,并基于裂纹尖端塑性钝化能将常见拉伸性能与平面断裂韧性联系起来,在常规拉伸性能参数的基础上,定量计算出了含孔连接板的断裂韧性值,通过引入与试样几何形状、孔型大小有关的Z参数,表征了含孔构件断裂失效过程中的平面应力和平面应变分布状态与组成比例.研究表明:(1)Z参数联系了材料断裂韧性与构件断裂韧性,反映了含孔构件的几何形状与开孔大小对构件断裂韧性值的影响;(2)含孔拉伸试样的断裂韧性敏感于开孔在垂直于拉伸方向上的尺寸,并随该尺寸的增加而降低;(3)含孔拉伸试样的屈服应力,强度极限等强度指标主要受开孔沿垂直于拉伸方向的尺寸影响,而几乎与开孔在拉伸方向上的尺寸变化无关,但含孔拉伸试样的延伸率则正好与此相反. 相似文献