scholarly journals Characterization of the Friction Coefficient of Aluminum Alloy 6061 in Ultra-Precision Machining

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 336 ◽  
Author(s):  
Hailong Wang ◽  
Tao Zhang ◽  
Sujuan Wang ◽  
Suet To
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Surface Generation ◽  
Precision Machining ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Friction Coefficients ◽  
Aluminum Alloy 6061 ◽  
Ultra Precision ◽  
Alloy 6061

Aluminum alloy 6061(Al6061), an Al-Mg-Si alloy, is a precipitation-hardened alloy. The generation of precipitate affects its mechanical properties, and induces a worse surface finish during diamond cutting. The friction coefficients of the tool-chip and tool-workpiece interfaces influence temperature rise, and are therefore important predictors of tool wear and surface integrity during the diamond cutting of Al6061. This study investigated the relationship between precipitate generation and the friction coefficients of Al6061. Groups of experiments were conducted to study the influence of temperature and heating time on the number of precipitates and the friction coefficients. The results show that the generation of AlFeSi particles induces cracks, scratch marks and pits on diamond-machined Al6061 and affects the cutting forces. Moreover, the variation trend of the friction coefficient of Al6061 under different heating conditions agrees well with that of the number of AlFeSi particles. This implies that, during ultra-precision machining of precipitation-hardened alloys, cutting-induced heat causes precipitates to form on the chips and machined surface, changing their material properties. This affects the tool-workpiece and tool–chip contact conditions and the mechanisms of chip formation and surface generation in ultra-precision machining.

scholarly journals Development of Elastoplastic-Damage Model of AlFeSi Phase for Aluminum Alloy 6061

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 954
Author(s):  
Hailong Wang ◽  
Wenping Deng ◽  
Tao Zhang ◽  
Jianhua Yao ◽  
Sujuan Wang
Keyword(s):  
Aluminum Alloy ◽  
Constitutive Model ◽  
Material Properties ◽  
Damage Model ◽  
Scratch Test ◽  
Aluminum Alloy 6061 ◽  
Ultra Precision ◽  
Simulation Results ◽  
Alloy 6061 ◽  
Elastoplastic Damage

Material properties affect the surface finishing in ultra-precision diamond cutting (UPDC), especially for aluminum alloy 6061 (Al6061) in which the cutting-induced temperature rise generates different types of precipitates on the machined surface. The precipitates generation not only changes the material properties but also induces imperfections on the generated surface, therefore increasing surface roughness for Al6061 in UPDC. To investigate precipitate effect so as to make a more precise control for the surface quality of the diamond turned Al6061, it is necessary to confirm the compositions and material properties of the precipitates. Previous studies have indicated that the major precipitate that induces scratch marks on the diamond turned Al6061 is an AlFeSi phase with the composition of Al86.1Fe8.3Si5.6. Therefore, in this paper, to study the material properties of the AlFeSi phase and its influences on ultra-precision machining of Al6061, an elastoplastic-damage model is proposed to build an elastoplastic constitutive model and a damage failure constitutive model of Al86.1Fe8.3Si5.6. By integrating finite element (FE) simulation and JMatPro, an efficient method is proposed to confirm the physical and thermophysical properties, temperature-phase transition characteristics, as well as the stress–strain curves of Al86.1Fe8.3Si5.6. Based on the developed elastoplastic-damage parameters of Al86.1Fe8.3Si5.6, FE simulations of the scratch test for Al86.1Fe8.3Si5.6 are conducted to verify the developed elastoplastic-damage model. Al86.1Fe8.3Si5.6 is prepared and scratch test experiments are carried out to compare with the simulation results, which indicated that, the simulation results agree well with those from scratch tests and the deviation of the scratch force in X-axis direction is less than 6.5%.

Characterization of Cutting-Induced Heat Generation in Ultra-Precision Milling of Aluminium Alloy 6061

2013 ◽  
Vol 552 ◽  
pp. 201-206
Author(s):  
Su Juan Wang ◽  
Suet To ◽  
Xin Du Chen
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Heat Generation ◽  
Feed Rate ◽  
Dimensional Accuracy ◽  
Precision Machining ◽  
Machined Surface ◽  
Single Crystal Diamond ◽  
Ultra Precision ◽  
Alloy 6061

The technology of ultra-precision machining with single crystal diamond tool produces advanced components with higher dimensional accuracy and better surface quality. The cutting-induced heat results in high temperature and stress at the chip-tool and tool-workpiece interfaces therefore affects the materials and the cutting tool as well as the surface quality. In the ultra-precision machining of al6061, the cutting-induced heat generates precipitates on the machined surface and those precipitates induce imperfections on the machined surface. This paper uses the time-temperature-precipitation characteristics of aluminum alloy 6061 (al6061) to investigate the effect of feed rate on the cutting-induced heat generation in ultra-precision multi-axis milling process. The effect of feed rate and feed direction on the generation of precipitates and surface roughness in ultra-precision raster milling (UPRM) is studied. Experimental results show that heat generation in horizontal cutting is less than that in vertical cutting and a larger feed rate generates more heat on the machined workpiece. A smaller feed rate produces a better surface finish and under a larger feed rate, scratch marks are produced by the generated precipitates and increase surface roughness.

scholarly journals An Investigation of the Cutting Strategy for the Machining of Polar Microstructures Used in Ultra-Precision Machining Optical Precision Measurement

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 755
Author(s):  
Chen-Yang Zhao ◽  
Chi-Fai Cheung ◽  
Wen-Peng Fu
Keyword(s):  
Precision Measurement ◽  
Detection Algorithm ◽  
Surface Generation ◽  
Precision Machining ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Ultra Precision ◽  
Transition Points ◽  
Cutting Strategy

In this paper, an investigation of cutting strategy is presented for the optimization of machining parameters in the ultra-precision machining of polar microstructures, which are used for optical precision measurement. The critical machining parameters affecting the surface generation and surface quality in the machining of polar microstructures are studied. Hence, the critical ranges of machining parameters have been determined through a series of cutting simulations, as well as cutting experiments. First of all, the influence of field of view (FOV) is investigated. After that, theoretical modeling of polar microstructures is built to generate the simulated surface topography of polar microstructures. A feature point detection algorithm is built for image processing of polar microstructures. Hence, an experimental investigation of the influence of cutting tool geometry, depth of cut, and groove spacing of polar microstructures was conducted. There are transition points from which the patterns of surface generation of polar microstructures vary with the machining parameters. The optimization of machining parameters and determination of the optimized cutting strategy are undertaken in the ultra-precision machining of polar microstructures.

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