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为摸清再生铝棒生产项目污染物排放情况,系统梳理再生铝棒生产项目典型生产工艺,逐一分析各生产环节的污染物产生情况,其中重点关注的污染物是废气和固体废物。全面排查再生铝棒生产项目各环节的污染物产生,有助于再生铝棒行业绿色可持续发展。 相似文献
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研究了.Net框架下C/S模式的金属热处理计算机辅助工艺设计(MHTCAPP)系统的开发。使用C#语言作为前台开发工具,Microsoft SQL Server作为后台数据库管理,以保证系统稳定、高效运行。基于软件生命周期法,从需求分析、总体设计、数据库设计以及详细设计等方面深入分析了系统的构建方法。MHTCAPP系统实现了常规热处理工艺的计算机辅助设计,结果可靠。系统提供了关于材料信息、工艺信息的多模式查询功能;具有可更新、可拓展性,并具有用户权限设置功能,保证系统数据安全。 相似文献
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针对增材制造过程中形成的缺陷会对工件造成不可逆的影响,分析了冷金属过渡(Cold metal transfer, CMT)增材制造过程的焊接电流信号和焊接电压信号,提出了一种基于时间序列算法的CMT增材制造缺陷在线监测方法。设置不同的焊接工况,收集良好组和缺陷组的原始焊接电流和焊接电压信号,使用SAX(Symbolic aggregate approximation)算法对数据进行预处理。使用随机森林模型对数值型数据再分类,达到实时监测的效果;同时为突出SAX算法的优越性,设置对比试验组,将原始的焊接电流数据直接放入随机森林模型进行分类。结果表明,原始焊接电流组的测试集准确率为80%,SAX算法数据预处理组的测试集准确率为96%。
相似文献6.
着眼新工科背景下对于工科大学生创新实践能力的培养要求,以材料科学与工程专业为例,基于中国大学生材料热处理创新创业大赛的学科竞赛,以《金属热处理原理与工艺》课程的系统性教学和综合设计性实验为抓手,以加强专业课程与学科竞赛联动及融合学科竞赛与人才培养体系为目的,解决单纯课堂理论教学的不足,探索工科专业课程课堂教学,强化学生参与、注重学生动手实践和综合素质的培养,真正实现“以赛促教、以赛促学、教学促赛、赛学促创”互动升级效果,着力培养新时代的创新型人才,为创新型人才的培养提供新思路,积极主动适应高等教育改革新常态。 相似文献
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为研究火车轮在模锻成形过程中内部金属流动及淬火加热、踏面淬火中的换热系数和温度变化,利用有限元软件对其模锻成形及热处理过程进行数值模拟分析,并结合黄金分割优化法对综合换热系数进行了反传热计算。结果表明:模锻过程中,辐板与上模接触区域的等效应变最大,轮辋外侧变形相对较小,踏面附近区域变形较均匀;在淬火加热过程中,换热系数随工件表面温度升高而增加,当温度在500℃以下时,换热系数随温度的升高而快速增加,500℃以后,增速缓慢,800℃时,换热系数达0.15 kW·(m^2·℃)^-1;踏面淬火时,在700℃以下,随温度下降,换热系数迅速增大,300℃时达到峰值3.1 kW·(m2·℃)^-1,在250℃以下,换热系数稍有下降,100℃时换热系数为2.5 kW·(m2·℃)^-1。 相似文献
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Study on interfacial heat transfer coefficient at metal/die interface during high pressure die casting process of AZ91D alloy 总被引:1,自引:0,他引:1
The high pressure die casting (HPDC) process is one of the fastest growing and most efficient methods for the production of complex shape castings of magnesium and aluminum alloys in today's manufacturing industry. In this study, a high pressure die casting experiment using AZ91D magnesium alloy was conducted, and the temperature profiles inside the die were measured. By using a computer program based on solving the inverse heat problem, the metal/die interfacial heat transfer coefficient (IHTC) was calculated and studied. The results show that the IHTC between the metal and die increases right after the liquid metal is brought into the cavity by the plunger, and decreases as the solidification process of the liquid metal proceeds until the liquid metal is completely solidified, when the IHTC tends to be stable. The interfacial heat transfer coefficient shows different characteristics under different casting wall thicknesses and varies with the change of solidification behavior. 相似文献
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The interfacial heat transfer coefficient(IHTC) between the casting and the mould is essential to the numerical simulation as one of boundary conditions. A new inverse method was presented according to the Tikhonov regularization theory. A regularized functional was established and the regularization parameter was deduced. The functional was solved to determine the interfacial heat transfer coefficient by using the sensitivity coefficient and Newton-Raphson iteration method. The temperature measurement experiment was done to ZL102 sand mold casting, and the appropriate mathematical model of the IHTC was established. Moreover, the regularization method was used to determinate the IHTC. The results indicate that the regularization method is very efficient in overcoming the ill-posedness of the inverse heat conduction problem(IHCP), and ensuring the accuracy and stability of the solutions. 相似文献
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行星轧制过程中滑动系数的研究 总被引:1,自引:0,他引:1
采用理论分析方法,通过对行星轧制过程中横截面处的金属流动情况以及轧件的受力情况和扭矩的计算方法进行分析,得到了轴向滑动系数以及切向滑动系数的计算方法,将其与有限元模拟计算的结果进行对比分析。结果表明:变形区内的切向速度先缓慢减小,然后急剧减小到最小值,再有所增大;而变形区内轴向速度先缓慢增加,再急速增大,随后有个缓慢变化区,最后有所增大。本方法计算得到的滑动系数的变化趋势与采用有限元仿真分析得到的结果变化趋势是一致的;验证了该理论计算方法的正确性。通过对轧制变形区内的滑动系数进行理论计算,可以更为准确地描述轧制过程中的金属流动规律。 相似文献
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针对薄铝板淬火过程,本文采用不同函数形式描述淬火换热系数,并借助ABAQUS有限元软件进行温度场和位移场模拟,得到换热系数和位移场的关系。基于试验所得翘曲位移反求换热系数,并对所选取的函数形式进行了优选。 相似文献
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In this paper,the research progress of the interfacial heat transfer in high pressure die casting(HPDC)is reviewed.Results including determination of the interfacial heat transfer coefficient(IHTC),influence of casting thickness,process parameters and casting alloys on the IHTC are summarized and discussed.A thermal boundary condition model was developed based on the two correlations:(a)IHTC and casting solid fraction and(b)IHTC peak value and initial die surface temperature.The boundary model was then applied during the determination of the temperature field in HPDC and excellent agreement was found. 相似文献