| Description |
A superior surface quality/integrity is required to maximize/optimize a component's service life and its performance. The machining process inflicts high temperatures and stresses/strains on the surface of the component, effectively influencing surface integrity. The objective of this work is to concurrently improve the surface integrity of the machined subsurface and improve tool tribology by Targeting a Minimum Quantity Cutting Fluid (TMQCF) during machining. This study optimizes machining temperatures to improve surface integrity by applying the TMQCF along the tool-chip contact area and the flank work-piece contact area. The study's hypothesis is heat produced in the machining process, if controlled aptly, can improve subsurface integrity and machining performance. To test the hypothesis, a study is conducted by machining different steels with different TMQCF applications. Experiments determined the effectiveness of targeted cutting fluid on annealed AISI 1045 steel and on quenched and tempered 300 M steel in improving the local subsurface integrity. Metrics for surface integrity (per ANSI B211.1) and tool surface tribology are used to estimate the effectiveness of the targeted cutting fluid application in the machining process. The research plan included collecting cutting force data using a tool dynamometer and machining temperature profiles using an Infra-Red camera in situ. This plan is used to determine the TMQCF's effects on the machined surface integrity, tool-chip interface conditions, and machining performance. iv The results show that the TMQCF application improves subsurface integrity, tool tribology, and chip control with a minimal environmental and economic cost. The results also show that the magnitude of variation in the subsurface residual stresses with different coated tools can be attributed to differences in thermal conductivity of the coatings and sharpness on the cutting tools. Finally, the experimental and modeling results show that tool geometrical feature effects are amplified when combined with the TMQCF application. Combined with a targeted cutting fluid application strategy, this work illuminates improving cutting fluid delivery for creating surfaces with enhanced surface integrity. The results from this study potentially enable the industry to make better quality parts with higher productivity and reduced environmental impacts. |
