Milenin Andrij, Wróbel Mirosław, Kustra Piotr, Němeček Jiří
Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, 30-059 Cracow, Poland.
Faculty of Civil Engineering, Czech Technical University in Prague, 160 00 Prague, Czech Republic.
Materials (Basel). 2021 Dec 21;15(1):35. doi: 10.3390/ma15010035.
This paper examines the surface roughness of a thin brass wire (140-200 microns in diameter) after two dieless drawing (DD) processes, i.e., conventional dieless drawing (CDD) and incremental dieless drawing (IDD). In incremental dieless drawing, small increments in deformation were applied in several passes. It has been proven that the IDD process not only has a greater efficiency but also enables obtaining a wire with significantly lower surface roughness. The explanation for these effects is based on the results of the numerical modeling of both compared processes. The developed numerical model takes into consideration the initial roughness of the wire surface, shape and dimensions of grains, and their diversified mechanical properties. Nanoindentation measurements, microstructure, and plastometric studies allowed us to find the effective flow stress distribution in the grains. The IDD process was found to be much more stable and develop a much more uniform distribution of grain strain than the CDD process. More homogeneous deformation results in surface roughness reduction. Approximately 25-30% reduction in surface roughness of the wire produced by the IDD process was predicted by simulations and confirmed experimentally.
本文研究了经过两次无模拉拔（DD）工艺，即传统无模拉拔（CDD）和增量无模拉拔（IDD）后，直径为140 - 200微米的细黄铜丝的表面粗糙度。在增量无模拉拔中，在多次道次中施加小的变形增量。已经证明，IDD工艺不仅效率更高，而且能够获得表面粗糙度显著更低的金属丝。对这些效果的解释基于对两种对比工艺的数值模拟结果。所开发的数值模型考虑了金属丝表面的初始粗糙度、晶粒的形状和尺寸及其多样化的力学性能。纳米压痕测量、微观结构和塑性测量研究使我们能够找到晶粒中的有效流动应力分布。发现IDD工艺比CDD工艺更稳定，并且晶粒应变分布更均匀。更均匀的变形导致表面粗糙度降低。模拟预测并通过实验证实，IDD工艺生产的金属丝表面粗糙度降低了约25 - 30%。
