Journal of Modern Processes in Manufacturing and Production, Volume 10, No. 4, Autumn 2021 51 DOR: 20.1001.1.27170314.2021.10.4.4.9 Research Paper Experimental Study of the Effect of Different Spindle Speeds and Feed Rates in Dry Machining on a Brittle Material Mohammad Reza Safavipour 1 , Masoud Farahnakian 1* 1 Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran * Email of Corresponding Author: farahnakian@gmail.com Received: September 20, 2021; Accepted: January 13, 2022 Abstract Material removal modes in brittle material machining are divided into two categories: ductile modes and brittle modes. Many believe that there is a clear difference between energy costs in these two cases. Spindle speed (SS) and feed rate are the effective parameters in the material machining process. It is tried to conduct experimental studies on the effect of low spindle speeds and high feed rates on the turning of brittle material in this paper. Also, the tool geometry is an important factor in turning brittle materials; so the rake angle of the turning tool was changed for dry machining of a single- crystal workpiece. The results show that the surface roughness decreases by increasing the spindle speed and decreasing the feed rate, which reduces the surface damage significantly. The purpose of this experimental study is to investigate the effect of rotational speed and feed rate on surface roughness and surface texture in the lathe process of the workpiece using the ductile mode of machining and changes in the parameters of this process to control the configuration and dimensions of microstructures (micro craters, Surface pits, and micro-cracks). Keywords Machining, Spindle Speed, Feed Rate, Rake Angle, Surface Damage 1. Introduction Reducing surface damage on machining of the workpiece in the shortest time to receive the final machining plays an essential role in the final surface quality of the product and reducing manufacturing costs. Due to the increasing demand for higher precision components, surface roughness and surface texture of a machined part are essential factors in the production process. The material removal process in the machining of ductile materials occurs by plastic deformation which often creates a smooth surface without damage. Brittle regime machining (BRM) is characterized by the removal of material through the formation and diffusion of micro-cracks, micro craters, and surface pits at the workpiece surface. Therefore, brittle materials such as germanium, Silicon, Glass, and industrial ceramics can be a machine in ductile mode by changing the machining parameters and tool geometry. Researchers have considered the tool feed rate as an effective operational parameter on brittle material machining and have stated that changes in the feed cause a position change in the critical chip thickness along with the tool nose [1]. Due to the complexity of interplaying between tool geometry,