李华平
,
柴广跃
,
彭文达
,
阳英
,
高敏
,
郭宝平
,
牛憨笨
无机材料学报
doi:10.3724/SP.J.1077.2008.00114
通过实验和模拟拟合, 对微弧氧化过程中Al2O3膜表面的对流散热系数作了估计, 实验过程中发现Al2O3/Al界面在微观上也是一个冷却界面, Al 基体在冷却过程中起“热量中转”的作用, 熔池在淬冷过程中的大部分热量经过了邻近区域的Al2O3膜或者铝基体. 通过热模拟得到的纵深各点温度-时间曲线来表征微熔区的淬冷过程. 通过对各节点的相对冷却速度比较, 阐述了淬冷过程对α-Al2O3分布和Al2O3膜表面形貌的影响, 压力因素在微观结构形成过程中所产生的影响作了粗略的分析.
关键词:
铝合金
,
microarc oxidation
,
quenching
,
microstructure
,
FEM
常旭
,
唐春安
,
张后全
,
张永彬
,
张亚芳
无机材料学报
基于多层梁模型,在考虑材料非均匀性的基础上,采用有限元数值模拟的方法研究 了层状复合陶瓷的断裂行为.给出了复合陶瓷模型在三点弯曲的加载条件下,裂纹拐折和扩展 的过程,验证了层状复合陶瓷的主要增韧机理:裂纹沿软层界面拐折耗能.在此基础上,研究 了不同参数条件下,层状复合陶瓷韧性的变化规律.
关键词:
层状复合陶瓷
,
toughening
,
FEM
,
numerical simulation
付志强
,
杜凤山
,
安子军
,
段利英
,
于辉
,
杨帆
钢铁
为了研究方矩形管辊弯成型时金属的流动规律,结合某厂实际生产工艺,建立了方矩形管辊弯成型的三维弹塑性非线性有限元模型,基于该模型得到的仿真结果与现场轧制结果基本一致,通过对仿真结果的分析分别得到了方矩形管辊弯成型时长边、角部、短边和纵向上的内、中、外层的金属流动规律.研究结果表明:在厚度方向稳定段处,从外层到内层的金属流动规律是不一致的,长边处的不一致性要比短边处明显;在纵向上前、中、后段处,外层上的金属流动规律存在较大的差异,前段与后段的外、内层上的金属流动规律是相反的.分析结果为预测最终成型尺寸精度与辊弯成形工艺参数的制定提供了理论依据.
关键词:
方矩形管
,
辊弯成型
,
金属流动规律
,
有限元
陈鑫
,
刘靖
,
韩静涛
中国冶金
doi:10.13228/j.boyuan.issn1006-9356.20140090
包覆浇铸后的复合铸坯虽然已具有冶金结合,但热轧过程中,道次变形量若确定不合理将在界面处产生附加应力,附加应力值的大小将影响热轧后复合板的界面结合情况.应用ABAQUS有限元软件对包覆浇铸304不锈钢/高硼不锈钢/304不锈钢复合铸坯的热轧过程进行了有限元模拟,有限元模拟结果显示,当道次变形量大于17％时,覆层及芯层变形协调性变差,复合板界面将遭到破坏.实际热轧试验验证了有限元模拟结果的正确性,为包覆浇铸复合铸坯的热轧提供了有利的工艺参数.
关键词:
包覆复合板
,
有限元模拟
,
道次压下量
,
变形协调性
Y.N. Kwon and Y.-W. Chang(Center for Advanced Aerospace Materials (CAAM)
,
Pohang University of Science and Technology
,
Pohang 790-784. Korea Manuscript received 26 August 1996)
金属学报(英文版)
Superplastic forming of a thin sheet into complex shape is an important manufacturing process especially in aerospace industry. The main objective of modeling the superplastic forming process is to predict the forming pressure-time cycle to maintain the optimum strain rate and the resulting thickness distribution. There have been many attempts to model superplastic forming process using the various techniques including finite element method. However, most of these attempts so far have disregarded the strain hardening effect which occurs in several superplastic materials. In this study,we have used ABAQUS finite element code to predict the suitable processing variables during an axisymmetric cup forming of Supral 100 and 7075Al alloys to examine the strain hardening effects on forming. The performance of numerical results was then compared with the experimental results.
关键词:
:superplastic forming
,
null
,
null
,
null
,
null
L. H. Lang
,
D. C. Kang
,
S. H. Zhang
,
Z. R. Wang
,
S. J. Yuan
,
K. B. Nielsen and J. Dancket 1) Department of Materials Engineering
,
Harbin Institute of Technology
,
Harbin 150001
,
China 2) Aalberg University
,
Denmark
金属学报(英文版)
In this paper, the forming features of tapered rectangular box during hydrodynamic deep drawing are studied by means of FEM.The effect rules of square blank corner corner amount on body wrinkling are recognized and corresponding methods are discussed. At last, the results of FEM are verified by experi- ment.
关键词:
sheet metal forming
,
null
,
null
