Linear Sawing Apparatus and its Evaluation for Research Into High Speed Bone Sawing

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.

Author(s):  
Rimah S. Al Aridi ◽  
Ahmad M. R. Baydoun ◽  
Ramsey F. Hamade

Abstract In metal cutting, some of the generated forces do not contribute to chip formation. These forces are referred to as plowing forces and are induced mainly as result of the finite sharpness of the tool (cutting edge radius) and the tool’s land (flank). Determining the magnitude of these forces is essential to developing a better understanding of the mechanics and physics of applications that involve cutting at minimal feed values (e.g., micro-machining and vibration-assisted-micro-machining. It is well recognized that plowing forces increase with tool wear. This research estimates these forces by employing analytical and numerical simulations. An extensive experimental analysis is utilized to verify the simulated values of the plowing forces. The experimental verification is designed to measure these forces as a function of several cutting parameters. The developed methodology relates the plowing forces to geometric factors and process parameters such as cutting-edge radius, tool feed, and cutting speed.


2013 ◽  
Vol 652-654 ◽  
pp. 2218-2221 ◽  
Author(s):  
Li Bao An ◽  
Chun Guang Lu

Metal cutting indicates a specific category of processes in which unwanted material is removed from workpeice by single- or multi-point cutting tools for making products meeting prescribed specifications. Parameter optimization in metal cutting plays an important role in satisfying quality requirements of machined parts at low production cost or time. It requires optimal selection of cutting speed, feed rate, depth of cut, and the number of passes. A brief review of recent progress on the optimization of cutting parameters is introduced in the present work. Some new machining practices expending in recent years are involved including hard turning, dry cutting, high speed machining, machining of difficult-to-machine materials and composites. Modeling skills for creating optimization models and optimization techniques for solving optimal or near-optimal solutions are summarized and analyzed.


2016 ◽  
Vol 862 ◽  
pp. 3-10
Author(s):  
Marek Vrabeľ ◽  
Ildikó Maňková ◽  
Peter Ižol ◽  
Mária Franková ◽  
Miroslav Paľo

Titanium alloy Ti6Al4V represents one of the most frequently used alloys in medical as well as in aerospace industry and is considered as a difficult to cut material. In this paper, cutting experiments within throughput drilling were carried out under the varying cutting speed, feed and tool geometry (cutting edge radius and clearance angle). The effects of cutting speed feed and tool geometry on thrust force in drilling Ti6Al4V alloy were investigated applying design of experiment (DoE) according to Taguchi plan L16. The effect of above mentioned parameters was investigated through analysis of the S/N ratios (smaller is better) and ANOVA analysis. All analyses were performed using statistical software Minitab and Matlab. In the case of thrust force, the feed is the main influencing factor, followed by cutting speed, cutting edge radius and clearance angle.


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.


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.


2013 ◽  
Vol 797 ◽  
pp. 202-207
Author(s):  
Chang Ying Wang ◽  
Jia Jin Tian ◽  
Qing Long An ◽  
Ming Chen

Ultra-high-strength steel 30Cr3SiNiMoVA (30Cr3) which has excellent mechanical properties is usually used to manufacture the key parts in aviation industry. Precision hard milling is an efficiency way to machine 30Cr3 instead of grinding. Rounded cutting edge radius has important influence on the machining process due to small depth of cut. In order to better understanding the influence of rounded cutting edge radius, cutting forces, cutting temperature, critical depth of cut, etc., is analyzed by using finite element method (FEM). The results show that cutting forces in theydirection are more sensitively to the rounded cutting edge radii. Ploughing effect is also observed at the end of the climb milling process and it has significant influence on the quality of the machined surface. Simulation reveals that the increment of rounded cutting edge radius can lead to the increment of critical depth of cut correspondingly and the proportionality factor is about 14%.


Author(s):  
Kubilay Aslantas ◽  
Şükrü Ülker ◽  
Ömer Şahan ◽  
Danil Yu Pimenov ◽  
Khaled Giasin

AbstractMicroturning is a micromechanical machining process used to produce microcylindrical or axially symmetrical parts. Microcylindrical parts are mainly used in microfluidic systems, intravenous micromotors, microsurgical applications, optical lens applications, and microinjection systems. The workpiece diameter is very small in microturning and therefore is greatly affected by the cutting forces. For this reason, it is important to predict the cutting forces when machining miniature parts. In this study, an analytical mechanistic model of microturning is used to predict the cutting forces considering the tool nose radius. In the semi-empirically developed mechanistic model, the tool radius was considered. A series of semi-orthogonal microturning cutting tests were carried out to determine the cutting and edge force coefficients. The mechanistic model was generalized depending on the cutting speed and depth of cut by performing multilinear regression analysis. In the study, the depth of cut (ap = 30–90 µm) and feed values (f = 0.5–20 µm/rev) were selected considering the nose radius and edge radius of the cutting tool. The experiments were carried out under high-cutting speeds (Vc = 150–500 m/min) and microcutting conditions. Ti6Al4V alloy was used as the workpiece material and the tests were carried out under dry cutting conditions. Validation tests for different cutting parameters were carried out to validate the accuracy of the developed mechanistic model. The results showed that the difference between the mechanistic model and the experimental data was a minimum of 3% and a maximum of 24%. The maximum difference between the experimental and the model usually occurs in forces in the tangential direction. It has been observed that the developed model gives accurate results even at a depth of cut smaller than the nose radius and at feed values smaller than the edge radius.


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.


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.


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.


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