共查询到20条相似文献,搜索用时 125 毫秒
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运用有限元软件ABAQUS,采用基于扩展的Drucker-Prager的本构模型对药物片剂成形过程进行了数值模拟.获得了药物片剂压制成形的密度分布及成形力等相关数据.结果表明:随着压制深度的增加,片剂材料密度及成形力整体呈现增大趋势.药物片剂压制过程数值模拟得到的片剂材料流动规律及力学行为,将为实际成形中工艺参数的改善... 相似文献
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氢致裂纹试验及数值模拟技术国内外研究现状(2) 总被引:1,自引:0,他引:1
3 氢致裂纹数值模拟技术3.1 研究状况数值模拟是利用数学计算和数学分析的方法再现某一物理过程,可以加深对该过程发展规律的认识进而加以控制.近年来,随着对焊接热传导过程、焊接力学、金属相变热力学/动力学及传质过程研究的深入,一些焊接物理过程目前可以采用简化的数学模型加以描述.其中焊接热过程数值模拟、瞬时焊接应力/应变数值模拟、焊接区组织模拟及氢扩散与聚集行为数值模拟技术均取得了一定的成果.随着计算机软硬件技术的不断完善,计算机的计算能力和计算速度不断提高,采用近代计算机软硬件的开发成果对焊接氢致裂纹进行数值模拟逐渐成为可能.在焊接性数值模拟方面,近十年来,世界各地的焊接工作者进行了一些尝试,取得了一些成果.国际焊接学会(IIW)于80年代后期组建了焊接性数值模拟工作组,该工作组于l991年 相似文献
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针对Ag-Cu-Zn-Sn系多元金属混合粉料制备无镉中温银基钎料进行研究,探索压坯密度与压制压力、压制模量及压制速率的关系。采取理论分析、工艺实验和软件拟合曲线相结合的方法,构建了电磁压制条件下的高速率压型方程,为电磁压制工艺的数值模拟分析提供数学模型和相应的参数,提高数值仿真的准确性和可靠性。该结果为Ag-Cu-Zn-Sn系多元金属混合粉料进行合理的电磁压制工艺设计提供一定的理论价值和工程实践指导意义。 相似文献
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锻造铝合金轮毂摆动辗压制坯工序数值模拟技术 总被引:2,自引:2,他引:0
锻造铝合金轮毂由于其优越的性能成为轮毂制造业发展的必然趋势.摆动辗压制坯工序是锻造铝合金轮毂生产工艺中一步重要的工序.本文使用DEFORM-3D软件对锻造铝合金轮毂摆动辗压制坯过程进行数值模拟,考察了主要工艺参数对成形过程的影响,并确定了合理的始锻温度480℃和压下速度10mm·s-1.用已经确定的成形参数考察了0558.8mm铝合金轮毂制坯工序成形力的大小为2335kN,与实验结果2362kN非常接近.数值模拟结果可以为开发该工序设备确定主参数提供理论依据. 相似文献
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针对管道阴极保护数值模拟的应用现状,对阴极保护体系的控制方程以及三种常用边界条件做了简单的介绍。同时介绍了三种常用的数值计算方法以及国内外研究学者对这三种数值计算方法的应用情况,并对比分析了三种数值解法的优缺点。最后指出了目前管道阴极保护数值模拟技术存在的不足,并提出了相应的解决措施。 相似文献
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粉末压制过程运动仿真的研究 总被引:1,自引:0,他引:1
粉末压制过程的计算机模拟技术是用于指导和优化粉末冶金压制工艺和模具设计的关键技术,已成为粉末冶金工业发展的研究热点,简述了粉末压制过程计算机模拟系统中的运动仿真模真原理,结构以及主要功能,并提出了相应的设计方法。 相似文献
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Tungsten and tungsten-based alloys have wide applications in industries. Powder metallurgy is one of the major processes for production of tungsten parts, but tungsten parts with high density cannot be produced by this method. Two explosive compaction processes using converging underwater and no-water shock wave, were applied to compact tungsten powder in the present investigation. C4 as an explosive material with a detonation velocity of 8.2 km/s applied to consolidate amorphous powder with a mean grain size of 5 μm. The density and hardness of consolidated tungsten parts were determined and by scanning electron microscope (SEM) analyzed their fragment surfaces. In addition to explosion experiments, a numerical simulation of compaction processes conducted by use of LS-DYNA program. Finally, the experimental results of two processes and numerical simulation results of the same processes compared. The results indicated that the tungsten parts without cracks and with a hardness equal to 570 Vickers and a density equal to 18.5 g/cm3 can be obtained by underwater shock wave compaction method. 相似文献
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概述现代粉末冶金材料和技术的发展现状。介绍了传统粉末冶金材料与先进粉末冶金材料的基本特性、应用情况及发展趋势,较系统介绍了机械合金化、粉末注射成形、温压成形、喷射成形、微波烧结、放电等离子烧结、自蔓延高温合成、烧结硬化等新技术的研究与开发状况。内容分(一)、(二)两部分,分两期发表。 相似文献
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现代粉末冶金材料和技术发展现状(二) 总被引:3,自引:0,他引:3
概述现代粉末冶金材料和技术的发展现状。介绍了传统粉末冶金材料与先进粉末冶金材料的基本特性、应用情况及发展趋势,较系统介绍了机械合金化、粉末注射成形、温压成形、喷射成形、微波烧结、放电等离子烧结、自蔓延高温合成、烧结硬化等新技术的研究与开发状况。内容分一、二两部分,分两期发表。 相似文献
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1 INTRODUCTIONDiecompactionofpowderhasbeenusedincom ponentsmanufacturingindifferentfields[1~ 4 ] .Inen gineeringapplications ,greencom 相似文献
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Warm compaction powder metallurgy of Cu 总被引:2,自引:1,他引:2
A series of experiments were carried out using different admixed lubricant contents, different compaction pressures and temperatures in order to study the warm compaction of copper powder. Results show that too much admixed lubricant will lead to the squeeze out of the lubricant from the compact during the warm compaction processing of Cu powder. Results also show that blisters can be found in sintered samples that contain lubricant less than 0.15%(mass fraction). Optimal warm compaction parameters for producing high density powder metallurgy copper material are obtained. Compacts with green density of 8.6 g/cm^3 and a sintered density of 8.83 g/cm3 can be produced by warm compacting the Cu powder, which contains 0.2% admixed lubricant, and is compacted at 145℃ with a pressure of 700 MPa. 相似文献
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This work presents a numerical study on the dynamic high velocity compaction of the metal powder. The analysis of the process is based on a mesoscopic approach using multi-speed lattice Boltzmann method. The boundary condition and the relaxation time are tailored to the situation. The dynamic compaction process is vividly presented and the shock wave can be easily found in the simulation. The density is analyzed in order to explore the mechanism of the high velocity compaction. 相似文献
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M. Moss R. Lapovok C. J. Bettles 《JOM Journal of the Minerals, Metals and Materials Society》2007,59(8):54-57
Applications for magnesium powders have generally been restricted to the area of pyrotechnology, but with improved safety
measures and novel processing technologies there are now more opportunities opening up for magnesium powder metallurgy components.
Conventional powder metallurgy involving liquid phase sintering may not be a viable option, however, due to the high reactivity
of molten magnesium in air. Solid-state consolidation processes are therefore desirable, with direct powder extrusion and
equal channel angular pressing (ECAP) offering real alternatives to the conventional press/sinter routes. With this move toward
purely solid-state metallurgy come opportunities for alternative alloy design strategies, potentially leading to microstructures
not readily achieved through traditional casting routes. This paper will discuss the suitability of the ECAP route for magnesium
powder compaction and explore the novel alloying strategies that become available with the success of these solid-state powder
metallurgical processes. 相似文献