Machining Characteristics of High Speed Dry Milling of Biodegradable Magnesium-Calcium Alloy

Author(s):  
M. Salahshoor ◽  
Y. B. Guo

Metallic degradable biomaterials have attracted a huge attention lately for orthopedic fixation applications. Binary magnesium and calcium (Mg-Ca) alloys have emerged as a promising choice in terms of biocompatibility to avoid stress shielding and provide sufficient mechanical strength. In this paper, efficient and ecologic machining of a lab-made Mg-Ca alloy with 0.8 wt% calcium, cutting speeds of up to 47 m/s, and without coolant are investigated. Polycrystalline diamond inserts are applied and the possibilities of flank built-up formation, chip ignition, and tool wear are sought during the cutting experiments with the aid of a developed on-line, optical monitoring system. Chip morphology characteristics produced by different combinations of cutting parameters, i.e. cutting speed, feed, and depth of cut are studied.

Author(s):  
Zengqiang Wang ◽  
Zhanfei Zhang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Kunyang Lin ◽  
...  

Abstract High speed cutting (HSC) technology has the characteristics of high material removal rates and high machining precision. In order to study the relationships between chip morphology and machining surface characteristic in high speed cutting of superalloy Inconel718. High-speed orthogonal cutting experiment are carried out by used a high speed cutting device based on split Hopkinson pressure bar (SHPB). The specimen surfaces and collected chips were then detected with optical microscope, scanning electron microscope and three-dimensional surface profile measuring instrument. The results show that within the experimental parameters (cutting speed from 8–16m/s, depth of cut 0.1–0.5mm), the obtained chips are sawtooth chips and periodic micro-ripple appear on the machined surface. With the cutting speed increases, machining surface roughness is decreases from 1.4 to 0.99μm, and the amplitude of periodic ripples also decreases. With the cutting depth increases, the machining surface roughness increases from 0.96 to 5.12μm and surface topography becomes worse. With the increase of cutting speed and depth of cut, the chips are transform from continues sawtooth to sawtooth fragment. By comparing the frequency of surface ripples and sawtooth chips, it is found that they are highly consistent.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 617 ◽  
Author(s):  
Ireneusz Zagórski ◽  
Jarosław Korpysa

Surface roughness is among the key indicators describing the quality of machined surfaces. Although it is an aggregate of several factors, the condition of the surface is largely determined by the type of tool and the operational parameters of machining. This study sought to examine the effect that particular machining parameters have on the quality of the surface. The investigated operation was the high-speed dry milling of a magnesium alloy with a polycrystalline diamond (PCD) cutting tool dedicated for light metal applications. Magnesium alloys have low density, and thus are commonly used in the aerospace or automotive industries. The state of the Mg surfaces was assessed using the 2D surface roughness parameters, measured on the lateral and the end face of the specimens, and the end-face 3D area roughness parameters. The description of the surfaces was complemented with the surface topography maps and the Abbott–Firestone curves of the specimens. Most 2D roughness parameters were to a limited extent affected by the changes in the cutting speed and the axial depth of cut, therefore, the results from the measurements were subjected to statistical analysis. From the data comparison, it emerged that PCD-tipped tools are resilient to changes in the cutting parameters and produce a high-quality surface finish.


Author(s):  
M. Salahshoor ◽  
Y. B. Guo

Biodegradable magnesium-calcium (Mg-Ca) implants have the ability to gradually dissolve and absorb into the human body after implantation. The critical issue that hinders the application of Mg-Ca implants is its poor corrosion resistance to human body fluids. A promising approach to tackle this issue is tailoring the surface integrity characteristics of the orthopedic implants to get an appropriate corrosion kinetic. High speed face milling of biodegradable Mg-Ca alloy is used in this study as a possible way to achieve that goal. Polycrystalline diamond inserts are used to avoid material adhesion and likely fire hazards. All the cutting tests are performed without using coolant to keep the manufacturing process ecological. High cutting speed of 40 m/s and 200 μm depth of cut are applied in a broad range of feed values to cover finish and rough cutting regimes. The effect of feed as a key machining parameter which defines the amount and duration of thermo-mechanical load and ultimately provides higher chances for surface integrity changes are investigated.


2009 ◽  
Vol 69-70 ◽  
pp. 418-422
Author(s):  
L.D. Wu ◽  
Cheng Yong Wang ◽  
D.H. Yu ◽  
Yue Xian Song

Hardened steel P20 at 50 HRC is milled at high speed by TiN coated and TiAlN coated solid carbide straight end mills, and the cutting forces and tool wear are measured. The result shows that TiAlN coated tool is more suitable for cutting hardened steel at high speed. Then the hardened steel is milled under different cutting parameters. It is indicated that the effect of cutting speed on cutting forces is small, but the effect of cutting speed on machine vibration should be considered. Increase feed per tooth or radial depth of cut will increase the cutting forces.


Author(s):  
A. Saravanapandi Solairajan ◽  
S. Alexraj ◽  
P. Vijaya Rajan ◽  
Godwin Jose

Glass fiber reinforced composite material was fabricated using E-glass fiber with unsaturated polyester resin. In Glass Fiber Reinforced Plastic (GFRP) composites, the matrix of polymer is reinforced with glass fibers. The surface quality and dimensional precision significantly affect the parts during their suitable life, particularly in cases where the components come in contact with other elements or materials. In the current study, GFRP is machined with two cases i.e. with and without Nano combinations in lathe. These machining studies were carried out on lathe using three different cutting tools: namely Carbide (K-20), Cubic Boron Nitrate (CBN) and Polycrystalline Diamond (PCD). The cutting parameters considered were cutting speed, feed, and depth of cut. Surface Finish is the most important parameter measured by main spindle and compares the value with another. A second order mathematical model in terms of cutting parameters was developed using RSM. The results specify the developed model is suitable for prediction of surface roughness in machining of GFRP composites.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1104 ◽  
Author(s):  
Adel T. Abbas ◽  
Neeraj Sharma ◽  
Saqib Anwar ◽  
Monis Luqman ◽  
Italo Tomaz ◽  
...  

Titanium alloys are widely used in various applications including biomedicine, aerospace, marine, energy, and chemical industries because of their superior characteristics such as high hot strength and hardness, low density, and superior fracture toughness and corrosion resistance. However, there are different challenges when machining titanium alloys because of the high heat generated during cutting processes which adversely affects the product quality and process performance in general. Thus, optimization of the machining conditions while machining such alloys is necessary. In this work, an experimental investigation into the influence of different cutting parameters (i.e., depth of cut, cutting length, feed rate, and cutting speed) on surface roughness (Rz), flank wear (VB), power consumption as well as the material removal rate (MRR) during high-speed turning of Ti-6Al-4V alloy is presented and discussed. In addition, a backpropagation neural network (BPNN) along with the technique for order of preference by similarity to ideal solution (TOPSIS)-fuzzy integrated approach was employed to model and optimize the overall cutting performance. It should be stated that the predicted values for all machining outputs demonstrated excellent agreement with the experimental values at the selected optimal solution. In addition, the selected optimal solution did not provide the best performance for each measured output, but it achieved a balance among all studied responses.


2015 ◽  
Vol 1115 ◽  
pp. 104-108
Author(s):  
Muataz Hazza F. Al Hazza ◽  
Erry Y.T. Adesta ◽  
Muhammad Hasibul Hasan ◽  
Norhashimah Shaffiar

Selecting the cutting conditions to optimize the economics of machining process as assessed by energy machining cost is essential. The aim of this research is to determine the optimum cutting parameters that minimize the energy cost needed for removing one cubic centimetre of material in High Speed Hard Turning (HSHT) process. To achieve that, a set of experimental machining data to cut hardened steel AISI 4340 was obtained with different ranges of cutting speed, feed rate, depth of cut and negative rake angle using mixed ceramic as a cutting tool. Regression models have been developed by using Box-Behnken design as a design of experiment. Then, the Simulated Annealing Algorithm (SAA) has been used to optimize the cutting parameters. The data collected was statistically modelled. The results show that the range of minimum energy cost to remove one cubic centimetre of material for the three techniques can be achieved in the range of 300 to 308 as a cutting speed, -12 for cutting rake angle, 0.125 as a feed rate and 0.15 as a depth of cut.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5677
Author(s):  
Elshaimaa Abdelnasser ◽  
Azza Barakat ◽  
Samar Elsanabary ◽  
Ahmed Nassef ◽  
Ahmed Elkaseer

This article presents the results of an experimental investigation into the machinability of Ti6Al4V alloy during hard turning, including both conventional and high-speed machining, using polycrystalline diamond (PCD) inserts. A central composite design of experiment procedure was followed to examine the effects of variable process parameters; feed rate, cutting speed and depth of cut (each at five levels) and their interaction effects on surface roughness and cutting temperature as process responses. The results revealed that cutting temperature increased with increasing cutting speed and decreasing feed rate in both conventional and high-speed machining. It was found that high-speed machining showed an average increase in cutting temperature of 65% compared with conventional machining. Nevertheless, high-speed machining showed better performance in terms of lower surface roughness despite using higher feed rates compared to conventional machining. High-speed machining of Ti6Al4V showed an improvement in surface roughness of 11% compared with conventional machining, with a 207% increase in metal removal rate (MRR) which offered the opportunity to increase productivity. Finally, an inverse relationship was verified between generated cutting temperature and surface roughness. This was attributed mainly to the high cutting temperature generated, softening, and decreasing strength of the material in the vicinity of the cutting zone which in turn enabled smoother machining and reduced surface roughness.


Author(s):  
John J. Pearlman ◽  
Anil Saigal ◽  
Thomas P. James

Previous research into the cutting mechanics of bone sawing has been primarily approached from the perspective of orthogonal metal machining with a single edge cutting tool. This was a natural progression from the larger body of knowledge on the mechanics of metal cutting. However, there are significant differences between typical orthogonal metal cutting parameters and those encountered in bone sawing, such as anisotropic material behavior, depth of cut on the order of cutting edge radius, chip formation mechanism in the context of a saw blade kerf, non-orthogonal considerations of set saw blade teeth, and cutting speed to name a few. In the present study, an attempt is made to overcome these shortcomings by employing a unique sawing fixture, developed to establish cutting speeds equivalent to those of typical sagittal saws used in orthopaedic procedures. The apparatus was developed for research into bone sawing mechanics and is not intended to be a commercial sawing machine. The sawing fixture incorporates the cutting speed possible with lathe operations, as well as the linear cutting capabilities of a milling machine. Depths of cut are on the same order of magnitude as the cutting edge radius typical to saw blade teeth. Initial measurements of cutting and thrust force, obtained with this new experimental equipment, are compared to previous work.


2011 ◽  
Vol 189-193 ◽  
pp. 3142-3147 ◽  
Author(s):  
Dong Qiang Gao ◽  
Zhong Yan Li ◽  
Zhi Yun Mao

A model of stress and temperature field is established on nickel-based alloy cutting by finite element modeling and dynamic numerical simulating, and then combining high-speed machining test and orthogonality analysis method, the influence law of cutting parameters on the cutting force and tool wear has been researched, and the tool life and cutting force prediction model based on cutting parameters has been obtained. Finally, by genetic algorithm method cutting parameters are selected reasonably and optimized. The result shows that the bonding wear is main tool wear, and the influence of cutting speed on cutting force is smaller than feed per tooth and axial depth of cut.


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