【摘要】 介绍了反复镦压工艺的原理、路线及特点,并研究了纯铜反复镦压后的组织、硬度及拉伸性能。结果表明,反复镦压可在不改变试样形状和尺寸的情况下累积很大的应变。退火态纯铜经多道次镦压后晶粒明显细化。3道次镦压前,纯铜的平均显微硬度随应变的增加快速增加,随镦压次数的进一步增加,硬度上升的幅度下降。多道次镦压后纯铜的抗拉强度明显提高,从退火态的198.5 MPa提高到最高约488.8 MPa。镦压后纯铜的断后伸长率明显下降,但仍在15%以上,其断裂性质仍属韧性断裂。研究结果说明反复镦压是一种有应用前景的制备块体细晶材料的方法。更多还原

【Abstract】 The principle,processing routes and characteristics of cyclic channel die compression(CCDC) process were introduced.Microstructure,microhardness and tensile property of pure copper subjected to CCDC process were investigated.The results show that large strain can be accumulated through CCDC process without changing the size and shape of the specimen.The grains of as-annealed copper are refined obviously after multi-pass CCDC.The average Vickers microhardness increases rapidly before 3 passes CCDC and then becomes stable with further increasing passes of CCDC.Ultimate tensile strength of the pure copper by CCDC is improved from initial 198.5 MPa to the maximum value of 488.8 MPa.However,its elongation to failure decreases after CCDC,but the elongation is still over 15%.Fracture mechanism of pure copper after CCDC belongs to ductile fracture.The investigation shows that CCDC is a promising method for producing bulk ultra-fine grained materials.更多还原