Vegetable oil-based nanofluid minimum quantity lubrication turning: Academic review and perspectives

Owing to superior physio-chemical characteristics, titanium alloys are widely adopted in numerous fields such as medical, aerospace, and military applications. However, titanium alloys have poor machinability due to its low thermal conductivity which results in high temperature during machining. Numerous lubrication and cooling techniques have already been employed to reduce the harmful environmental footprints and temperature elevation and to improve the machining of titanium alloys. In this current work, an attempt has been made to evaluate the effectiveness of two cooling and lubrication techniques namely cryogenic cooling and hybrid nanoadditive–based minimum quantity lubrication (MQL). The key objective of this experimental research is to compare the influence of cryogenic CO2 and hybrid nanofluid–based MQL techniques for turning Ti–6Al–4V. The used hybrid nanofluid is alumina (Al2O3) with multi-walled carbon nanotubes (MWCNTs) dispersed in vegetable oil. Taguchi-based L9 orthogonal-array was used for the design of the experiment. The design variables were cutting speed, feed rate, and cooling technique. Results showed that the hybrid nanoadditives reduced the average surface roughness by 8.72%, cutting force by 11.8%, and increased the tool life by 23% in comparison with the cryogenic cooling. Nevertheless, the cryogenic technique showed a reduction of 11.2% in cutting temperature compared to the MQL-hybrid nanofluids at low and high levels of cutting speed and feed rate. In this regard, a milestone has been achieved by implementing two different sustainable cooling/lubrication techniques.

Effects of hybrid Al2O3-CNT nanofluids and cryogenic cooling on machining of Ti–6Al–4V

Laser surface texturing and related techniques for enhancing tribological performance of engineering materials: A review

Tribology of enhanced turning using biolubricants: A comparative assessment

In the present study, the machinability indices of surface grinding of AISI D2 steel under dry, flood cooling, and minimum quantity lubrication (MQL) conditions are compared. The comparison was confined within three responses, namely, the surface quality, surface temperature, and normal force. For deeper insight, the surface topography of MQL-assisted ground surface was analyzed too. Furthermore, the statistical analysis of variance (ANOVA) was employed to extract the major influencing factors on the above-mentioned responses. Apart from this, the multi-objective optimization by Grey⁻Taguchi method was performed to suggest the best parameter settings for system-wide optimal performance. The central composite experimental design plan was adopted to orient the inputs wherein the inclusion of MQL flow rate as an input adds addition novelty to this study. The mathematical models were formulated using Response Surface Methodology (RSM). It was found that the developed models are statistically significant, with optimum conditions of depth of cut of 15 µm, table speed of 3 m/min, cutting speed 25 m/min, and MQL flow rate 250 mL/h. It was also found that MQL outperformed the dry as well as wet condition in surface grinding due to its effective penetration ability and improved heat dissipation property.

https://www.mdpi.com/1996-1944/11/11/2269/pdf

Multi-Objective Optimization for Grinding of AISI D2 Steel with Al₂O₃ Wheel under MQL.

Cutting performance of textured polycrystalline diamond tools with composite lyophilic/lyophobic wettabilities

Friction is the main factor related to the reliability and durability of mechanical equipment. The main problems of machining difficult-to-cut material are violent friction of cutting area and an increase in tool wear caused by high cutting temperature. To solve these problems, surface texture has become an effective way since it can reduce cutting force and temperature and decrease the friction between the tool and chip. In this study, three kinds of hybrid textures, including variable density texture, variable shape texture, and variable shape and density texture were designed and experimentally investigated and compared with the homothetic texture and untextured surface. The textures were fabricated on the rake face of the carbide tools by pulsed fiber laser with different processing parameters. Experiments regarding cutting of Ti6Al4V titanium alloy were carried out with untextured tool and different textured tools under the condition of dry cutting and minimum quantity lubrication (MQL). Results indicate that the cutting tools with variable shape and density texture possess advantages mostly related to improvement of cutting performance, which is manifested as the reduction in thrust force, average friction coefficient, and tool wear. Particularly, under MQL conditions, the average friction coefficient of the tool with the variable shape and density hybrid texture is the smallest, which is 9.362% smaller than that of the tool without texture and 5.81% smaller than that of the tool with homothetic texture. Furthermore, the antifriction mechanism of the hybrid texture was analyzed in detail.

Cutting performance of carbide tools with hybrid texture

Tribological Properties of Textured Cemented Carbide Surfaces of Different Wettability Produced by Pulse Laser

The invention discloses a manufacturing method for a lyophilic-lyophobic combined textured tool surface, and belongs to the technical field of mechanical cutting tool manufacturing A micro-groove texture is arranged on the surface of a tool The inner portions of micro-grooves are in the lyophilic state, other areas of the micro-grooves are micro-nanometer structure functional layers in the lyophobic state, and therefore the lyophilic-lyophobic combined textured tool surface is formed Under the lubrication condition, lubricating liquid rapidly moves on the surface of the lyophobic layers and is automatically collected to the inner portions of the lyophilic micro-grooves and rapidly conveyed to a cutting area By designing parameters of the lyophilic-lyophobic combined tool surface and micro-nanometer texture parameters, the lubrication state of the cutting area can be actively regulated, controlled and improved, and therefore the friction force of tool-workpiece and tool-chip interfaces is reduced, and guarantees are provided for reducing friction and abrasion of the tool The lyophilic-lyophobic combined textured tool surface can be widely applied to high-speed cutting and cutting of materials hard to cut, the tool life can be prolonged, and the machining quality and accuracy can be improved

Manufacturing method for lyophilic-lyophobic combined textured tool surface

The invention discloses a preparation method of an oleophobic cutter with a micro-nano composite structure surface, and belongs to the technical field of manufacturing of mechanical cutting tools. A micro-nano composite structure can be machined on the surface of a cutter by using a laser processing technology, and is micron projections formed on the surface of the laser-processed cutter and nano particles on the micron projections; and a certain surface treatment is performed for the composite structure to form an oleophobic cutter surface with the micro-nano composite structure. Under the lubricating condition, because of lipophobicity of the cutter surface, cutting liquid can be supplied to a cutter-chip interface more quickly, the lubricating state of a cutting area can be improved, the friction force of the cutter-chip interface is reduced, the guarantee is provided for friction reduction and wear reduction of the cutter, the cutting temperature can be lowered, and the bonding phenomenon of the cutter surface is relieved; and the oleophobic cutter can be widely applied to cutting and high-speed cutting of difficult cutting materials (such as titanium alloys, ultrahigh-strength steel, austenitic stainless steel), so that the cutter durability and the workpiece surface quality can be greatly improved.

Xiuqing Hao

Papers

Cutting performance of textured polycrystalline diamond tools with composite lyophilic/lyophobic wettabilities

Cutting performance of carbide tools with hybrid texture

Tribological Properties of Textured Cemented Carbide Surfaces of Different Wettability Produced by Pulse Laser

Manufacturing method for lyophilic-lyophobic combined textured tool surface

Preparation method of oleophobic cutter with micro-nano composite structure surface