Machinability improvement of compacted graphite irons in milling process with supercritical CO2-based MQL. (August 2021)

• Record Type: Journal Article
• Authors: Tu, Luqiang; Chen, Jie; An, Qinglong; Ming, Weiwei; Xu, Jinyang; Chen, Ming; Lin, Liangliang; Yang, Zhenming
• Is Part Of: Journal of manufacturing processes. Volume 68:Part A(2021)
• Page Start: 154
• Page End: 168
• Publication Date: 2021-08
• Subjects: Supercritical CO2 -- MQL -- Cast iron -- Machinability -- Surface integrity; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2021.05.044
• Languages: English
• ISSNs: 1526-6125

Abstract

Abstract: Compacted graphite iron (CGI) has become one of the most potential and promising materials for diesel engines contributing to automotive industry applications because of its outstanding mechanical properties over flake graphite iron (FGI). However, the poor machinability of CGI has hindered it to be widely employed in potential automotive industry. In this paper, a supercritical CO2 -based MQL technique was introduced to improve the machinability of CGI. The machinability of CGI was systematically evaluated considering the cutting force, cutting temperature, surface integrity and tool wear under various cutting parameters (cutting speed, feed rate, depth of cut) and machining atmospheres ( i.e., dry, supercritical carbon dioxide (ScCO2 ), supercritical CO2 -based minimum quantity lubrication with oil-on-water droplets cutting fluid (ScCO2 -MQL)) compared to FGI and nodular graphite iron (NGI) in the milling process. The results show that among three machining atmospheres, the lowest values regarding cutting force, cutting temperature, and surface roughness values are obtained under the ScCO2 -MQL atmosphere. Furthermore, the tool wear mechanisms were revealed to be abrasion wear and adhesion wear. The ScCO2 -MQL exhibited excellent superiority in cutting force and temperature, surface integrity, and tool life compared to dry and ScCO2 conditions due to its outstanding cooling and lubricant effects. The results demonstrated that using the advanced ScCO2 -MQL technique can substantially improve the machinability of the compact graphite cast irons. Highlights: A supercritical CO2 -based MQL (ScCO2 -MQL) technique was introduced to improve the machinability of compacted graphite irons ScCO2 -MQL exhibited excellent superiority in cutting force and temperature, surface integrity, and tool life Wear mechanisms of TiAlN-coated cutting tools were demonstrated to be abrasion and adhesion wear