Sustainable High Speed Dry Cutting of Magnesium Alloys

2012 ◽  
Vol 723 ◽  
pp. 3-13
Author(s):  
Yue Bin Guo ◽  
Zhan Qiang Liu
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Energy Use ◽  
Internal State ◽  
Polycrystalline Diamond ◽  
Mg Alloys ◽  
Plasticity Model ◽  
Machining Performance ◽  
Dry Cutting ◽  
Pcd Tools

Magnesium (Mg) components can significantly reduce energy use due to their low densities compared to the majority alloys. Mg alloys are often machined to fit individual cases. However, process mechanics by high-speed dry cutting of Mg alloys are poorly understood. This study focuses on machining ability of biomedical magnesium-calcium (Mg-Ca) alloys. First, it presents a modeling approach of mechanical behavior of Mg-Ca0.8 (wt %) alloy under cutting regimes using the internal state variable (ISV) plasticity model. Then, the ISV plasticity model is implemented to simulate high speed dry cutting of Mg-Ca0.8 alloy by finite element method. Last, machining performance in the context of sustainability is discussed. Excellent surface finish can be achieved in the range of high cutting speeds. Continuous chip formation predicted by the finite element simulation is verified by high speed dry cutting of Mg-Ca0.8 using polycrystalline diamond (PCD) inserts. Chip ignition as the most hazardous aspect in machining Mg alloys does not occur for in high-speed dry cutting with sharp PCD tools. The predicted temperature distribution well explains the reason for the absence of chip ignition in high speed dry cutting of Mg-Ca0.8 alloy. A mechanism of built-up layer (BUL) formation is proposed.

Cutting Mechanics of High Speed Dry Machining of Magnesium-Calcium Biomedical Alloy Using Internal State Variable Plasticity Model

2011 ◽  
Author(s):  
M. Salahshoor ◽  
Y. B. Guo
Keyword(s):  
Mechanical Properties ◽  
Chip Formation ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Internal State ◽  
Material Behavior ◽  
Internal State Variable ◽  
Plasticity Model ◽  
Dry Cutting ◽  
State Variable

Magnesium-Calcium (MgCa) alloys have become attractive orthopedic biomaterials due to their biodegradability, biocompatibility, and congruent mechanical properties with bone tissues. However, process mechanics of machining biomedical MgCa alloys is poorly understood. Mechanical properties of the biomedical magnesium alloy at high strain rates and large strains are determined by using the split-Hopkinson pressure bar testing method. Internal state variable (ISV) plasticity model is implemented to understand the dynamic material behavior under cutting conditions. A finite element simulation model has been developed to study the chip formation during high speed dry cutting of MgCa0.8 (wt %) alloy. Continuous chip formation predicted by the FE simulation is verified by high speed dry face milling of MgCa0.8 using polycrystalline diamond (PCD) inserts. Chip ignition is known as the most hazardous aspect of machining Mg alloys. The predicted temperature distributions may well explain the reason for machining safety of high-speed dry cutting of MgCa0.8 alloy.

scholarly journals The Performance of Polycrystalline Diamond (PCD) Tools Machined by Abrasive Grinding and Electrical Discharge Grinding (EDG) in High-Speed Turning

2021 ◽  
Vol 5 (2) ◽  
pp. 34
Author(s):  
Guangxian Li ◽  
Ge Wu ◽  
Wencheng Pan ◽  
Rizwan Abdul Rahman Rashid ◽  
Suresh Palanisamy ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
High Speed ◽  
Flank Wear ◽  
Polycrystalline Diamond ◽  
Machining Efficiency ◽  
Crater Wear ◽  
Wear Process ◽  
High Speed Turning ◽  
Tools Wear ◽  
Pcd Tools

Polycrystalline diamond (PCD) tools are widely used in industry due to their outstanding physical properties. However, the ultra-high hardness of PCD significantly limits the machining efficiency of conventional abrasive grinding processes, which are utilized to manufacture PCD tools. In contrast, electrical discharge grinding (EDG) has significantly higher machining efficiency because of its unique material removal mechanism. In this study, the quality and performance of PCD tools machined by abrasive grinding and EDG were investigated. The performance of cutting tools consisted of different PCD materials was tested by high-speed turning of titanium alloy Ti6Al4V. Flank wear and crater wear were investigated by analyzing the worn profile, micro morphology, chemical decomposition, and cutting forces. The results showed that an adhesive-abrasive process dominated the processes of flank wear and crater wear. Tool material loss in the wear process was caused by the development of thermal cracks. The development of PCD tools’ wear made of small-sized diamond grains was a steady adhesion-abrasion process without any catastrophic damage. In contrast, a large-scale fracture happened in the wear process of PCD tools made of large-sized diamond grains. Adhesive wear was more severe on the PCD tools machined by EDG.

Predicting the High Speed Cutting Process of Titanium Alloy by Finite Element Method

2011 ◽  
Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Cutting Process ◽  
Fe Model ◽  
Dry Cutting ◽  
Friction Coefficients ◽  
Machining Conditions

To predict the cutting forces and cutting temperatures accurately in high speed dry cutting Ti-6Al-4V alloy, a Finite Element (FE) model is established based on ABAQUS. The tool-chip-work friction coefficients are calculated analytically using the measured cutting forces and chip morphology parameter obtained by conducting the orthogonal (2-D) machining tests. It reveals that the friction coefficients between tool-work are 3∼7 times larger than that between tool-chip, and the friction coefficients of tool-chip-work vary with feed rates. The analysis provides a better reference for the tool-work-chip friction coefficients than that given by literature empirically regardless of machining conditions. The FE model is capable of effectively simulating the high speed dry cutting process of Ti-6Al-4V alloy based on the modified Johnson-Cook model and tool-work-chip friction coefficients obtained analytically. The FE model is further validated in terms of predicted forces and the chip morphology. The predicted cutting force, thrust force and resultant force by the FE model agree well with the experimentally measured forces. The errors in terms of the predicted average value of chip pitch and the distance between chip valley and chip peak are smaller. The FE model further predicts the cutting temperature and residual stresses during high speed dry cutting of Ti-6Al-4V alloy. The maximum tool temperatures exist along the round tool edge, and the residual stress profiles along the machined surface are hook-shaped regardless of machining conditions.

Finite Element Analysis of Residual Stresses in High-Speed Dry Cutting of Biodegradable Magnesium-Calcium Alloy

2012 ◽  
Author(s):  
M. Salahshoor ◽  
Y. B. Guo
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Material Behavior ◽  
Human Anatomy ◽  
Dry Cutting ◽  
Stress Profiles ◽  
Cutting Regimes

Magnesium-Calcium (Mg-Ca) alloys have become attractive biodegradable orthopedic implant biomaterials recently. Residual stresses are proven to be very influential on degradation rate of these alloys in human anatomy. Due to time and cost inhibitive reasons, development of finite element models to predict residual stress profiles under various cutting regimes is highly desirable. In this context, a finite element model of orthogonal cutting without explicit chip formation is developed by adopting plowing depth approach in order to predict process induced residual stresses in high speed dry cutting of Mg-Ca0.8 (wt %) using diamond tools. Mechanical properties of Mg-Ca0.8 alloy at high strain rates and large strains are determined using split-Hopkinson pressure bar test. Internal state variable (ISV) plasticity model is implemented to model the material behavior under cutting regimes. The residual stress evolution process and effects of plowing speed and plowing depth on residual stress profiles are studied. Residual stress measurements are performed utilizing X-ray diffraction technique for validation purposes.

Study on the Wear Mechanism of PCD Tools in High-Speed Milling of Al-Si Alloy

2011 ◽  
Vol 381 ◽  
pp. 16-19 ◽  
Author(s):  
Yong Guo Wang ◽  
Biao Liu ◽  
Jiong Yi Song ◽  
Xiang Ping Yan ◽  
Kang Mei Wu
Keyword(s):  
Wear Mechanism ◽  
High Speed ◽  
Energy Dispersive Spectrometer ◽  
Cutting Speed ◽  
Polycrystalline Diamond ◽  
Machining Process ◽  
Diffusion Wear ◽  
Milling Tool ◽  
Pcd Tools ◽  
And Diffusion

Polycrystalline diamond (PCD) tools have been obtained increasing application in aluminum alloy processing industry due to the excellent surface finish and tool life comparing with other traditional tools. Investigation of the wear mechanism of PCD milling tool for machining Al-Si alloy at cutting speed of 5000m/min (n=12732r/min) has been performed. The wear morphology of tool has been studied by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Results show that PCD milling tool suffers from abrasive wear and diffusion wear on the flank face and adhesive wear on the rake face in the machining process.

High Speed Cutting of Titanium Alloy with PCD Tools

2008 ◽  
Vol 389-390 ◽  
pp. 157-162 ◽  
Author(s):  
Michiko Ota ◽  
Junya Okida ◽  
Takashi Harada ◽  
Naohiro Toda ◽  
Hitoshi Sumiya
Keyword(s):  
Thermal Conductivity ◽  
Titanium Alloy ◽  
High Speed ◽  
Polycrystalline Diamond ◽  
High Speed Cutting ◽  
Pcd Tool ◽  
Tool Edge ◽  
Cemented Carbide Tools ◽  
Pcd Tools ◽  
High Pressure Coolant

When cutting titanium alloy, the temperature of a cutting tool edge is easy to rise and the tool edge is tend to be worn away quickly because the titanium alloy has the characteristics of low thermal conductivity and high chemical activity. Therefore, it is difficult to achieve a balance between the productivity and the tool life in cutting the titanium alloy, namely, low-speed cutting must be carried out at present. To examine the possibility of the improvement in the cutting efficiency, a PCD (polycrystalline diamond) tool having high thermal conductivity was adopted to the cutting of titanium alloy and its cutting performance was investigated. The PCD tool was found to have excellent flank wear resistance compared with conventional cemented carbide tools. It was also revealed that unprecedented high speed cutting become possible by use of PCD tool with an application of high pressure coolant.

Performance of Cutting Tools in High Speed Milling of SiCp/Al Composites

2012 ◽  
Vol 591-593 ◽  
pp. 311-314 ◽  
Author(s):  
Yang Jun Wang ◽  
Ming Qiang Pan ◽  
Tao Chen ◽  
Ji Zhu Liu ◽  
Li Guo Chen
Keyword(s):  
High Speed ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Optical Microscope ◽  
Coated Tools ◽  
Tools Wear ◽  
Pcd Tools

This paper presents an experimental study in milling of SiCp/Al composites on a high precision machine by using chemical vapor deposition(CVD) diamond coated tools and polycrystalline diamond (PCD) tools. The tool wear was observed and measured by an optical microscope and a scanning electron microscope (SEM). The results show that the coating rupture causes the failure of the CVD diamond coated tools. The PCD tools’ wear is less. At the relatively low cutting speed, the wear pattern of PCD tools is the flank wear which caused by the abrasion of SiC particles. Due to the low cutting temperature, the graphitization of PCD tools does not happen. The wear mechanism of PCD tools will be the abrasive and adhesive wear.

Machining Induced Defects and the Influence Factors when Diamond Turning of SiCp/Al Composites

2007 ◽  
Vol 10-12 ◽  
pp. 626-630 ◽  
Author(s):  
Y.F. Ge ◽  
Jiu Hua Xu ◽  
Hui Yang ◽  
S.B. Luo ◽  
Yu Can Fu
Keyword(s):  
Surface Quality ◽  
Volume Fraction ◽  
Single Point ◽  
Influence Factors ◽  
Polycrystalline Diamond ◽  
High Volume ◽  
Diamond Turning ◽  
Dry Cutting ◽  
Machined Surface ◽  
Pcd Tools

Ultra-precision turning tests on SiCp/2024Al and SiCp/ZL101A composites were carried out to investigate the surface quality using single point diamond tools (SPDT) and polycrystalline diamond (PCD) cutters. Examined by SEM, the machined surfaces took on many defects such as pits, voids, microcracks, grooves, protuberances, matrix tearing and so on. The results showed that surface quality debased with increasing feed rate or using of high volume fraction materials. Dry cutting would deteriorate the surface finish. It was also pointed out that SPDT outperformed PCD tools although they produced the same surface roughness Ra. Microhardness measuring showed that the deformation layer was extended to 8–16μm below the machined surface.

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