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固体颗粒介质成形新工艺及变形研究 总被引:1,自引:0,他引:1
固体颗粒介质成形新工艺,是采用固体颗粒代替刚性凸模(或弹性体、液体)的作用,对金属板料成形的工艺。固体颗粒介质成形新工艺,即可以解决流体介质、粘性介质的密封难题,又具有内压非均匀分布、便于控制成形、提高材料成形极限、降低投资成本、所得零件表面质量高、成品率高的优点,且固体颗粒无工业污染,可重复使用。该工艺为材料的加工制备提供了新的方法和手段。利用塑性增量理论,对自由变形区任意一点的应变进行了分析,得到了自由变形区任一点的应变及厚度计算公式。采用固体颗粒介质成形工艺,进行板料成形试验,成功试制出多种典型工件;对试验件壁厚分布的计算值和实测值进行了比较,证明理论正确。 相似文献
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选用非金属颗粒(NMG)作为研究对象,通过体积压缩试验和NMG在高应力水平下的物理性能试验,得到NMG体积压缩曲线和扩展的Drucker-Prager线性模型参数;通过摩擦强度试验,得到NMG的Mohr-Coulomb模型参数,并与扩展的Drucker-Prager线性模型参数比对基本吻合;测定了NMG与板材在不同正压力下的摩擦因数曲线。以材料性能试验为基础,对基于固体颗粒介质的板材软模成形工艺进行数值分析;设计制造固体颗粒介质板材成形试验模具,成功制出抛物线形零件。结果表明:固体颗粒介质与板材表面作用所表现出的显著摩擦性能,可以极大限度地发挥板料的成形性能;其工艺控制简便,模具结构简单;成形工件具有表面质量好、贴模性好、精度高等优点,为板材的加工和制备提供了新的方法和手段。 相似文献
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粘性介质压力成形(ViscousPressureForming,VPF)是一种适合于难变形材料板金零件制造的软模成形工艺。采用粘性介质胀形实验研究了反向压力对5A02铝合金板料成形性能的影响,结果表明在一定范围内的反向压力有利于抑制板料的平面各向异性,而在更高的反向压力条件下板料具有更好的成形性。 相似文献
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粘性介质反向压力胀形对5A02铝合金板成形性的影响 总被引:1,自引:0,他引:1
粘性介质压力成形(Viscous Pressure Forming,VPF)是一种适合于难变形材料板金零件制造的软模成形工艺。采用粘性介质胀形实验研究了反向压力对5A02铝合金板料成形性能的影响,结果表明在一定范围内的反向压力有利于抑制板料的平面各向异性,而在更高的反向压力条件下板料具有更好的成形性。 相似文献
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鉴于传统的充液拉深中存在液体介质密封困难、装置复杂等问题,提出了以固体颗粒代替液体介质的新工艺,通过对拉深过程中筒壁的受力分析得出固体颗粒介质拉深新工艺可以有效的减小成形过程中筒壁的拉应力,有利于提高材料的成形极限。自行设计了试验模具,通过对LY12M板料的拉深试验,验证了固体颗粒介质拉深新工艺的可行性,试验获得的极限拉深系数达到了0.51,优于传统刚性模拉深工艺。 相似文献
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The anisotropy of stamped sheet metal exerts evident effects on the formability.Barlat six-component yield function was introduced into the elastoplastic ficite element formulation based on the principle of virtual veloci-ty and the discrete Kirchhoff triangular element model.The flanging earing in cylindrical cup drawing process of cir-cular sheet metal was numerically simulated.The influence of anisotropy on the forming process was studied. 相似文献
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针对φ600 mm圆锯片淬火后变形大、影响圆锯片使用性能的问题,基于数值计算法分析其淬火残余应力的分布特性。分析结果表明:在整个淬火过程中,圆锯片淬火有效残余应力表现为拉应力;淬火结束后,中心孔附近的应力最大,其次为外圆齿附近的应力,中心孔与外圆齿中间位置的应力最小。以淬火奥氏体形成温度和保温时间为优化变量,淬火残余应力为优化目标函数,用响应曲面优化法对圆锯片淬火参数进行优化。优化结果表明:当奥氏体形成温度837℃,保温时间5 min时,最低残余应力为199 MPa。 相似文献
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Nosing process of circular metal tubes in empty and polyurethane foam-filled conditions on a semispherical rigid die was analyzed by theoretical and experimental methods. A new theoretical model of plastic deformation of circular metal tubes was demonstrated during the nosing process on a rigid semispherical die. Based on the analytical model, some theoretical relations were calculated to estimate instantaneous forming load and dissipated energy of empty and foam-filled circular metal tubes versus axial displacement. Some circular brazen and aluminum tubes were prepared and shaped into semispherical nosed nozzles to verify the present theory. Comparison of theoretical predictions and the corresponding experimental measurements reveals that predicted load-displacement and dissipated energy-displacement diagrams by theoretical formulas have a good correlation with the corresponding experimental curves and it proves verity of the theory. Also, the present theory shows that dissipated energy and axial load of empty tubes depend on material type, wall thickness and diameter of the tubes and they are independent of tube initial length. Furthermore, the experimental results show that the presence of polyethylene Teflon-constraints increases ultimate axial displacement of the forming process. 相似文献
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S. Sezek C. Misirli B. Aksakal Y. Can 《Journal of Materials Engineering and Performance》2012,21(4):500-507
The upper bound (UBM) and finite element methods (FEM) both coupled with experiments have been conducted to analyze forming
performance, load prediction, and pressure analyses in a combined extrusion-forging process using square and circular die
orifices. The forming load was predicted by the UBM and the pressure distribution was analyzed by FEM and the performance
of both the methods was compared to each other. The required extrusion forging force for square die orifice was found to be
higher than in the circular die orifice. The highest pressures occurred on the edges of the square and circular orifices and
the pressures increased with increasing friction and deformation. Although extrusion force predictions were found to be slightly
higher in UBM than FEM, they were in good agreement with experimental results. The present analyses showed that UBM can be
used in rapid prediction of required extrusion-forging loads and material flow, and FEM is more suitable to use in pressure
distribution analysis for production of square and cylindrical parts. 相似文献
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通过对圆弧齿轮对中方法、加工实例等几个方面的详细分析,论述了圆弧齿轮(包括双圆弧齿轮)滚切加工时滚刀对中对齿轮啮合精度的影响,认为滚刀对中是保证齿轮啮合精度必不可少的手段之一。并对双圆弧齿轮的成形过程提出了自己的见解。 相似文献