Abstract

This research work focuses on the development of SS 304 specimens using the selective laser melting technique and analyses the microstructural modifications. Further, it correlates the evolution of microstructure with mechanical properties like microhardness, nanoindentation and tribological behaviour. The conventionally prepared as-cast SS 304 specimens were taken for comparison of the results obtained with the SLM technique. The diffraction pattern obtained from x-rays disclosed the absence of δ phase and confirmed that refinement of grains occurred in the structural level through decrease in the intensity of α peaks. Optical micrograph witnessed that the grains were in micron and sub-micron size. SEM images depicted the presence of columnar and cellular sub-grains within a grain which were in ultrafine level. The microhardness and nanoindentation results obtained for the SLM specimen were almost multiple times higher than the conventional as-cast specimens. There was a significant improvement in the wear resistance in the SLM specimens than the conventional as-cast specimens. From the results, SLM is found to be a favourable technique to manufacture metallic components in a way to obtain a good service life of engineering components.

Graphic Abstract

中文翻译：

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通过SLM技术开发的SS 304试样的微观结构演变与力学和摩擦学行为的相关性

摘要

这项研究工作专注于使用选择性激光熔化技术开发SS 304试样并分析其微观结构变化。此外，它将微观结构的演变与机械性能（如显微硬度，纳米压痕和摩擦学行为）相关联。取常规制备的SS 304试样用于比较SLM技术获得的结果。从x射线获得的衍射图显示出不存在δ相，并且证实了通过降低α峰强度在结构水平上发生了晶粒细化。光学显微照片表明，晶粒的大小为微米和亚微米。SEM图像描述了谷物中存在超细水平的柱状和蜂窝状亚晶粒。SLM样品获得的显微硬度和纳米压痕结果几乎是常规铸态样品的几倍。与传统铸态试样相比，SLM试样的耐磨性有了显着提高。从结果可以发现，SLM是一种获得金属零件的良好技术，从而获得了良好的工程零件使用寿命。

图形摘要