Cooling and lubrication techniques in grinding:A state-of-the-art review,applications,and sustainability assessment

Grinding technology is an essential manufacturing operation,in particular,when a component with a superfinishing and an ultra-resolution is yearned.Meeting the required strict quality checklist with maintaining a high level of productivity and sustainability is a substantive issue.The recent paper outlines the lubrication and cooling technologies and mediums that are used for grinding.Furthermore,it provides a basis for a critical assessment of the different lubrication/cooling techniques in terms of machining outputs,environmental impact,hygiene effect,etc.Meanwhile,the paper put light on the sustainability of different cooling/lubrication strategies.The sustainability of machining aims to get the product with the best accuracy and surface quality,minimum energy consumption,low environmental impact,reasonable economy,and minimum effect on worker’s health.The paper revealed that despite some cooling/lubrication mediums like mineral oils and semisynthetic,afford sufficient lubrication or cooling,they have a significant negative impact on the environment and public health.On the other hand,emulsions can overcome environmental problems but the economy and the energy consumption during grinding are still a matter of concern.Biodegradable and vegetable oils are considered eco-friendly oils,but they suffer from a lack of thermal stability which affects their ability of efficiently cooling.Using the cooling medium with the lowest amount can achieve the goal of the economy but it may be reflected negatively on the machinability.Furthermore,cryogenic lubrication doesn’t provide sufficient lubrication to reduce friction and hence energy consumption.The research described in the paper is such a comprehensive compilation of knowledge regarding the machinability and machining performance under different cooling and lubrication systems that it will aid the next generation of scientists in identifying current advancements as well as potential future directions of research on ecological aspects of machining for sustainability.

Effects of groove-textured surfaces filled with Sn-Ag-Cu and MXene-Ti_(3)C_(2) composite lubricants on tribological properties of CSS-42L bearing steel

To improve the tribological performance of CSS-42L bearing steel,smooth surfaces(SSs),groovetextured surfaces(GSs),GSs with Sn-Ag-Cu(GSs-SAC),and GSs with Sn-Ag-Cu-Ti_(3)C_(2)(GSs-SACT)were prepared on CSS-42L.In addition,experimental studies were conducted on tribological properties.The obtained results indicated that GSs-SACT exhibited the best anti-friction and noise reduction performances.These remarkable tribological performances were attributed to the synergistic effects of grooves,Sn-Ag-Cu,and MXene-Ti_(3)C_(2).The inconsistent rules of frictional forces were improved by the grooves and SACT,which inhibit the friction-induced noise.The micro-nano size-effects of MXene-Ti_(3)C_(2) enhanced the repairing effect and anti-friction property of composite lubricants,which improved the profile characteristics of GSs-SACT.

A comprehensive review on residual stresses in turning

Residual stresses induced during turning processes can affect thequality and performance of machined products,depending on its direction and magnitude.Residual stresses can be highly detrimental as they can lead to creeping,fatigue,and stress corrosion cracking.The final state of residual stresses in a workpiece depends on its material as well as the cutting-tool configuration such as tool geometry/coating,cooling and wear conditions,and process parameters including the cutting speed,depth-ofcut and feed-rate.However,there have been disagreements in some literatures regarding influences of the abovementioned factors on residual stresses due to different cutting conditions,tool parameters and workpiece materials used in the specific investigations.This review paper categorizes different methods in experimental,numerical and analytical approaches employed for determining induced residual stresses and their relationships with cutting conditions in a turning process.Discussion is presented for the effects of different cutting conditions and parameters on the final residual stresses state.