共查询到20条相似文献,搜索用时 46 毫秒
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随着电子元件之间集成度的提高,元件之间距离的减小,各个引脚之间间隙的减小,大大提高了封装的难度,因为电子元件的封装不仅要保证良好的电器性能还要满足基本的连接功能。微电子元件软钎焊成为决定产品性能的关键因素之一。采用数值模拟分析方法详细描述软钎焊时的电子元件引脚周围的温度场分布。通过使用COMSOL软件完成对模型的构建以及材料的加载,并且根据实际的情况分析定义边界条件,然后利用软件计算出温度分布并且模拟钎料的相变过程。 相似文献
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激光多层涂敷过程中的温度场测量与数值模拟 总被引:12,自引:0,他引:12
用多路热电偶对激光多层涂敷过程的温度场进行了实时测量,测量结果显示在激光多层涂敷过程中,工件的温度呈近似周期性的变化;在最初的两层时,基材内部的温度变化很剧烈,随着涂敷层数的增加,基材内部的温度逐渐上升,同时温度变化趋于平缓、采用测量数据作为边界条件对工件的温度场进行了有限差分数值模拟,研究表明,激光多层涂敷过程中熔池内的温度梯度在10^5--10^6K/m数量级,在工艺参数保持不变的情况下,激光熔池的尺寸随着涂敷层数增加而增大,而温度梯度则随之减小. 相似文献
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G.F.Yuan C.S.Ge X.Y.Zeng 《金属学报(英文版)》2004,17(1):43-46
The physical model of temperature field and thermal stress field are established in this paper,on which the numerical simulation with the assuming physical and laser milling parameters have been finished. The laser milling process can be explained. 相似文献
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EXPERIMENTAL RESEARCH AND NUMERICAL SIMULATION OF MOLD TEMPERATURE FIELD IN CONTINUOUS CASTING OF STEEL 总被引:1,自引:0,他引:1
X.S. Zheng M.H. Sha J.Z. Jin 《金属学报(英文版)》2006,19(3):176-182
Mold is the heart of the continuous casting machine. Heat transfer and solidification in a water cooled mold are the most important factors during the continuous casting of steel. For studying the temperature distribution of a mold wall, a simulated apparatus of mold was designed and experiments were performed by it. The measured results indicated that the mold wall temperature approaches the temperature of cooling-water. An equivalent thermal-conductivity coefficient was proposed and deduced on the basis of the conclusion of the experiments. This coefficient was applied to solve the heat transfer between the melt and cooling water, and to characterize the heat transfer capacity of the mold. By this equivalent thermal-conductivity coefficient, it is very easy and convenient to numerically simulate the solidification process of continuous casting. And the calculation results are in agreement with the experiments. The effects of casting speed and water flow rate on the mold temperature field were also discussed. 相似文献
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1.IntroductionAsmoreattentionispaidtosurfacereinforcing,differentkindsofsurfacereinforcingtechnologyhavebeendevelopedinthiscentury.Coat-casttechnologyisoneofthem.Coat-castisonekindofcastingtechnology,amethodofbrushingorpastingthebinder,fluxandalloypowderontheinnersurfaceofthecastingmodelsoastoobtainasolid,reliablecoatwithspecialpropertiesonthecastingsurfaceduringcasting.Asearlyas1913,A.D.Momsproposedthethoughts.FOrmerSovietscholarsstartedtostudythecoat-casttechnologyin1970s.Inaddition,Japa… 相似文献
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电磁铸造大板坯半连铸过程温度场的数值模拟 总被引:3,自引:0,他引:3
Al的电磁铸造为半连续铸造过程,它的数学模型是空间非稳态非齐次热传输方程,提出并证明了以t时刻板坯占有的空间作为计算域,采用三维非稳态热传导方程,计算下一时刻(t+△t)的温度场,并将温度场的位置随拉坯速度v的方向移动v△t,然后.将顶部空缺的v△t空间由浇注的金属熔液充满,此时的温度场即t+△t时刻板坯行进位置的温度场.由于三维非稳态热传导方程具有稳定收敛的计算格式,所编制的软件可通用于三维非稳态热传输过程.模拟了1860mm×510mmAl合金大板坯,与文献已有的实测结果相比较,基本吻合.模拟结果表明,在板坯表面液柱高度相同的情况下.拉坯速度越大,液穴越深 相似文献
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本文提出一种不含Si的镍基Ni-Cr-Co-B高温钎料.对一系列Ni-Cr-Co-B钎料的熔化特性、钎焊工艺性能、钎料组织以及钎焊接头的室温和高温强度、接头韧性进行了研究,并与标准镍基钎料BNi-1a和BNi-5进行了比较研究结果表明,Ni-Cr-Co-B钎料钎焊的高温合金接头的高温性能和韧性均超过标准镍基钎料. 相似文献
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PRESS FORMABILITY OF YAG LASER WELDED TRIP STEEL SHEETS 总被引:1,自引:0,他引:1
A. Nagasaka 《金属学报(英文版)》2002,15(1):21-25
The effects of YAG laser welding conditions on mechanical properties and press formability (bendability, stretch-formability and deep drawability) of high-strength transformation-induced plasticity-aided dual-phase (TDP) steel were investigated. Tensile tests and press forming tests have been conducted for laser butt welded joints between two pieces of the same steel. The tensile property and press formability were affected by the welding speed of 100 to 1100mm/min and the energy of 6 to 9J/pulse. Excellent press formability was obtained with the energy of 6J/pulse and the welding speed of 300mm/min. It was concluded that the excellent weldability of the TDP steel can be ascribed to the weld joint formation. 相似文献
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激光熔覆熔池二维准稳态流场及温度场的数值模拟 总被引:4,自引:0,他引:4
本文建立了二维准稳态激光熔覆熔池流场及温度场的数值模型,除考虑对流换热外,模型还考虑了局部大变形自由表面.在贴体正交曲线坐标系下采用了非交错网格SIMPLE算法离散求解动量方程,计算出了激光熔覆熔池自由表面形状和温度场、速度场及局部特征凝团参.数值结果表明,表面张力温度系数和扫描速度μ0对熔池自由表面形状及熔池内温度分布、速度分布有重要影响.同时进行激光熔覆的工艺实验,实测枝晶二次臂间距(SDAD)的实验结果和数值结果吻合良好. 相似文献
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NUMERICAL SIMULATION OF TEMPERATURE FIELD ON FLASH BUTT WELDING FOR HIGH MANGANESE STEELS 总被引:1,自引:0,他引:1
B.D. YuChina Railway Shanhaiguan Bridge Group Limited Company Shanhaiguan China W.D. Song F.C. Zhang College of Materials Science Engineering Yanshan University Qinhuangdao China 《金属学报(英文版)》2005,18(4)
1. IntroductionW ith the developm entofrailw ay tow ard high-speed,heavy-load,trans-regionaland seam less,high-erperform ancessuch aslongerservice life, betterfatigue-resistance and w ear-resistance are desired forthe frog system on the railw ay.M eanw hi… 相似文献