Abstract

In this study, Al-5Zn, Al-15Zn, Al-25Zn and Al-35Zn alloys containing 5, 15, 25 and 35 wt% Zn, respectively were produced by permanent mold casting. Their microstructures and mechanical properties were investigated using metallography and universal hardness and tensile tests. Cutting tests of the alloys produced were carried out in a vertical machining center. During the tests, the cutting forces were continuously measured and saved by a software. The roughness of the machined surfaces of the alloy samples was measured accordance with the standard of ISO 4287. It was observed that Al-(5–15)Zn alloys exhibit single phase (aluminum rich α) microstructure while Al-(25–35)Zn alloys exhibit two-phase microstructure consisting of α and zinc rich η. As the zinc content increased the hardness and tensile strength of the alloys increased, but their elongation to fracture decreased. Cutting force, surface roughness, formation of built-up edge (BUE) and built-up layer (BUL), and the size of the chip occurring in the machining of the alloys decreased with increasing zinc content. The machining of the Al-(5-35)Zn alloys with uncoated WC tools results in both lower cutting forces and better surface quality compared to titanium-aluminum-nitride (TiAlN) coated tools. The changes in the cutting properties of the tested alloys with the increasing zinc content were discussed in the based on changes in structural and mechanical properties.

Graphic Abstract

摘要

在这项研究中，通过永久铸模生产分别含有5、15、25和35重量％Zn的Al-5Zn，Al-15Zn，Al-25Zn和Al-35Zn合金。使用金相学，通用硬度和拉伸试验研究了它们的微观结构和力学性能。所生产合金的切削测试在立式加工中心进行。在测试过程中，切削力被连续测量并由软件保存。根据ISO 4287标准测量合金样品的加工表面粗糙度。观察到，Al-（5-15）Zn合金表现出单相（富铝α）微观结构，而Al-（25-35）锌合金具有由α和富锌η组成的两相微观结构。随着锌含量的增加，合金的硬度和抗拉强度增加，但其断裂伸长率下降。随着锌含量的增加，切削力，表面粗糙度，堆积边缘（BUE）和堆积层（BUL）的形成以及合金加工中产生的切屑尺寸减小。与氮化钛铝（TiAlN）涂层的刀具相比，使用未涂层的WC工具对Al-（5-35）Zn合金进行机械加工可降低切削力并提高表面质量。基于结构和机械性能的变化，讨论了随着锌含量的增加，被测合金的切削性能的变化。与氮化钛铝（TiAlN）涂层的刀具相比，使用未涂层的WC工具对Al-（5-35）Zn合金进行机械加工可降低切削力并提高表面质量。基于结构和机械性能的变化，讨论了随着锌含量的增加，被测合金的切削性能的变化。与氮化钛铝（TiAlN）涂层的刀具相比，使用未涂层的WC工具对Al-（5-35）Zn合金进行机械加工可降低切削力并提高表面质量。基于结构和机械性能的变化，讨论了随着锌含量的增加，被测合金的切削性能的变化。

图形摘要