【作者】 孙毅；

【导师】 高家诚；

【作者基本信息】 重庆大学 ， 材料学， 2001， 硕士

【摘要】 近年来，国外研制成功的带内冷却螺旋孔的硬质合金钻头，可以提高深孔加工的效率，钻削难加工材料，满足自动加工线及加工中心的需要。在切削加工过程中，可以及时地除掉加工面上的金属碎屑，还可以大大地延长硬质合金工具的寿命，减少更换时间，提高加工速度。 本文介绍了注射成型工艺的研究进展。从粉末冶金的注射成型工艺的发展出发，对比分析了几种生产内螺旋硬质合金棒材的工艺在实际生产上的优缺点，从而设计出了一套挤压硬质合金内螺旋冷却孔棒材的模具和适宜的加工工艺。 本论文研究了粉体挤压工艺的机理及关键技术。针对粉末金属成形具有材料非线性、几何非线性以及边界条件非线性特征，系统地讨论了几类大变形弹塑性有限元方程的列式和求解特点以及各自的适用范围，得到了用于粉末成形数值模拟的大变形U.L.法的有限元列式。建立了描述粉体屈服的理论，讨论了关联法则或非关联法则进行求解对模拟结果的影响，同时，对有限元离散误差评估、自适应网格划分技术、接触和摩擦问题进行了详细的阐述。 研究了粉体成形机理的模拟技术。在计算机上，对金属粉体塑性成形过程进行了数值模拟跟踪描述，并通过计算机图形系统演示挤压嘴处成形过程，从而揭示金属粉体的塑性流动规律、各种因素对变形行为的影响及成形过程中变形体和模具的各种力学场的分布。更多还原

【Abstract】 Recently, more and more end drilling tools will be used with parallel or twisted internal cooling channels with wider variation of the cooling location and very different pitches, because such channel multiply the lifetime, make the removal of chips much easier and improve the quality of cutting work in comparison with normal solid tools without internal cooling channels. The old twisting processes are replaced by newer processes which are cheaper and more exact. The present for new twisting processes which are patented, or for which patent applications have been submitted schematically and the outlook for further ration development of the extrusion process for a rod diameter of up to 50 mm is given.First of all, the developing progress of metal powder injection molding is introduced. Based on it, some processes of manufacturing helical twisted holes are compared, consisted of their Advantages and disadvantages.Then one process of molding helical twisted coolant holes is designed.The die set design and manufacture of powdered metal compacting is discussed.The developing of researh about powdered metal compacting principles and its key technology is analyzed and discussed, the properties of powdered metal compacting such as non-linear behavior of material, geometrical, and boundary condition, the difference between metal powder and pore-free material and the difficulties of simulation are examined.The computer simalation stechnology is discussed The integrated computer simalation analysis system is applied to show the deformation situation.更多还原