Effect of edge hone radius on chip formation and its microstructural characterization in hard milling of AISI H13 steel
Effect of edge hone radius on chip formation and its microstructural characterization in hard milling of AISI H13 steel
复制标题
AISI H13钢硬铣削时刃口珩磨半径对切屑形成及其显微组织表征的影响
DOI：
10.1007/s00170-018-1933-x
复制
发表时间：
2018-07-01
影响因子：
3.4
通讯作者：
Zhang, Jing
中科院分区：
文献类型：
--
作者：
Li, Binxun;Zhang, Song;Zhang, Jing
切屑的形成是加工过程中的一个关键因素，可以影响切削稳定性和加工表面的完整性，特别是锯齿状切屑的形成。本文研究了 AISI H13 钢 (50 +/- 1 HRC) 硬铣削过程中锯齿状切屑的形成与刃口珩磨半径的关系，涉及切屑形态、冶金和机械性能演变、化学成分分布以及锯齿状切屑形成的机制。通过光学显微镜、扫描电子显微镜（SEM）、纳米测试仪和X射线衍射（XRD）来确定芯片的微观结构表征。首先，研究了刃口珩磨半径对切屑形态和切屑颜色演变的影响。结果表明，锯齿齿距减小，分割程度与刃磨半径相反，芯片背面颜色逐渐从紫色演变为蓝色。其次，较大的边缘珩磨半径导致在芯片背面产生较厚的白色层，并且在绝热剪切带（ASB）内以及芯片背面上识别出较高的纳米硬度值。此外，观察到发生在芯片背面的相变的发生，这可以通过芯片背面的颜色进行半定量。此外，检测到的碳含量在绝热剪切带和芯片背面几乎保持不变，表明对纳米硬度变化没有影响。最后指出AISI H13钢硬铣削中锯齿状切屑形成的机制主要归因于绝热剪切伴随循环裂纹的形成，从而促进了分段程度。本研究是刀刃几何形状制备以及硬铣削过程控制的基础研究。
Chip formation as a key factor during the machining process can affect cutting stability and machined surface integrity, specifically the formation of saw-tooth chip. The saw-tooth chip formation with respect to edge hone radius during hard milling of AISI H13 steel (50 +/- 1 HRC) was investigated in this paper involving chip morphology, metallurgical and mechanical property evolution, chemical composition distribution, and the mechanism of saw-tooth chip formation. The chip microstructural characterization was determined by means of optical microscopy, scanning electronic microscopy (SEM), a nano-tester, and X-ray diffraction (XRD). First, the effect of edge hone radius on chip morphology and evolution of chip color has been investigated. The results highlight that saw-tooth pitch decreases while the degree of segmentation is opposite with edge hone radius and the chip back surface color evolves gradually from purple to blue. Secondly, larger edge hone radius induces a thicker white layer generated on chip back surface and a higher value of nano-hardness identified inside an adiabatic shear band (ASB) as well as on chip back surface. In addition, the occurrence of phase transformation which occurs on chip back surface is observed which can be semi-quantified by the chip back surface color. Furthermore, the detected carbon content almost keep unvaried both in adiabatic shear band and on chip back surface, showing no impact on nano-hardness variation. Finally, it is indicated that the mechanism of saw-tooth chip formation in hard milling of AISI H13 steel is mainly attributed to adiabatic shearing accompanying with cyclic crack formation which facilitates the degree of segmentation. This research is a basic study for tool edge geometry preparation as well as controlling hard milling process.