Evaluation and investigation of grinding process of biomedical polymer (PEEK)

Author(s):  
Mohammad Khoran ◽  
Bahman Azarhoushang ◽  
Hossein Amirabadi

Polyether ether ketone (PEEK) has been widely used in the medical engineering due to its high strength to weight ratio, creep and wear-resistance, and anti-allergically properties. Grinding is generally used to produce PEEK parts with high accuracy and surface quality requirements. In this research, the tool loading and the effect of cryogenic cooling in the grinding of PEEK are studied for the first time. It is shown that the generated heat in the grinding process, which is mainly influenced by the tool micro-topography, process parameter, and coolant lubricant has an important role in the surface integrity of PEEK. Additionally, the influence of specific material removal rate and the dressing speed ratio on the specific grinding energy of PEEK was studied. The input parameters of the grinding process that are investigated in this study include cutting speed (vs), depth of cut (ae), and feed rate (vft). To investigate the grinding wheel topography, the effects of dressing overlap ratio (Ud) and the dressing speed ratio (qd) were also investigated. Grinding force, surface roughness, and loading of the grinding wheel were considered as output parameters. The experiments were designed based on response surface methodology and the optimum cutting condition was obtained based on this method. The depth of cut and the dressing overlap ratio had respectively the maximum and minimum impact on the surface roughness and cutting forces. Additionally, the tool loading was mainly influenced by the cutting speed.

Author(s):  
Amritpal Singh ◽  
Rakesh Kumar

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters in the hard turning of EN36 steel under the dry cutting condition is done. The input control parameters selected for the present work was the cutting speed, feed and depth of cut. The objective of the present work is to minimize the surface roughness to obtain better surface finish and maximization of material removal rate for better productivity. The design of experiments was done with the help of Taguchi L9 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence value. From results, it was observed that feed is the most significant factor for surface roughness and the depth of cut is the most significant control parameter for Material removal rate.


2011 ◽  
Vol 264-265 ◽  
pp. 1154-1159
Author(s):  
Anayet Ullah Patwari ◽  
A.K.M. Nurul Amin ◽  
S. Alam

Titanium alloys are being widely used in the aerospace, biomedical and automotive industries because of their good strength-to-weight ratio and superior corrosion resistance. Surface roughness is one of the most important requirements in machining of Titanium alloys. This paper describes mathematically the effect of cutting parameters on Surface roughness in end milling of Ti6Al4V. The mathematical model for the surface roughness has been developed in terms of cutting speed, feed rate, and axial depth of cut using design of experiments and the response surface methodology (RSM). Central composite design was employed in developing the surface roughness models in relation to primary cutting parameters. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The developed RSM is coupled as a fitness function with genetic algorithm to predict the optimum cutting conditions leading to the least surface roughness value. MATLAB 7.0 toolbox for GA is used to develop GA program. The predicted results are in good agreement with the experimental one and hence the model can be efficiently used to achieve the minimum surface roughness value.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Amon Gasagara ◽  
Wuyin Jin ◽  
Angelique Uwimbabazi

This article presents a new model of the flat surface grinding process vibration conditions. The study establishes a particular analysis and comparison between the influence of the normal and tangential components of grinding forces on the vibration conditions of the process. The bifurcation diagrams are used to examine the process vibration conditions for the depth of cut and the cutting speed as the bifurcation parameters. The workpiece is considered to be rigid and the grinding wheel is modeled as a nonlinear two-degrees-of-freedom mass-spring-damper oscillator. To verify the model, experiments are carried out to analyze in the frequency domain the normal and tangential dynamic grinding forces. The results of the process model simulation show that the vibration condition is more affected by the normal component than the tangential component of the grinding forces. The results of the tested experimental conditions indicate that the cutting speed of 30 m/s can permit grinding at the depth of cut up to 0.02 mm without sacrificing the process of vibration behavior.


2019 ◽  
Vol 805 ◽  
pp. 3-7
Author(s):  
Manus Sriswat ◽  
Kittipong Kimapong ◽  
Atthakorn Chanchana

Grinding process is necessary final process of making cylindrical parts with less than Ra 0.4 surface roughness. Generally we cannot obtain good surface quality without grinding process. As the experience of the authors, using CBN (Cubic Boron Nitride) insert to turning cylindrical parts could be obtained Ra 0.438 surface roughness. The surface roughness result is similar to ground parts. This result becomes the main focus of the study. Authors study to find out factors affecting CBN performance in turning with CBN to obtain less than Ra 0.4 surface roughness. According to the study, it was found that tool contact area allied to surface roughness. The experiment is turning S45C medium carbon steel under the following condition: Cutting speed is 300 m./min, Feed is 0.05 mm./rev and depth of cut is 0.1 mm. Experiment under the same condition in different contact area. Modify contact area of CBN insert to be 5,10,15,20 and 25 mm. and testing in order. CBN insert standard type contact area is 0 mm. Compare test results of modified CBN inserts with standard type result. The results of experiments were as follows: 1) Turning steel with CBN contact area 10 mm. was obtained Ra 0.456 surface roughness, 2) Turning steel with CBN contact area 15 mm. was obtained Ra 0.293 surface roughness, Thus less than Ra 0.4 surface roughness.


2013 ◽  
Vol 315 ◽  
pp. 413-417 ◽  
Author(s):  
Mohsen Marani Barzani ◽  
Mohd Yusof Noordin ◽  
Ali Akhavan Farid ◽  
Saaed Farahany ◽  
Ali Davoudinejad

Surface roughness is an important output in different manufacturing processes. Its characteristic affects directly the performance of mechanical components and the fabrication cost. In this current work, an experimental investigation was conducted to determine the effects of various cutting speeds and feed rates on surface roughness in turning the untreated and Sb-treated Al-11%Si alloys. Experimental trials carried out using PVD TIN coated inserts. Experiments accomplished under oblique dry cutting when three different cutting speeds have been used at 70, 130 and 250 m/min with feed rates of 0.05, 0.1 and 0.15 mm/rev, whereas depth of cut kept constant at 0.05 mm. The results showed that Sb-treated Al-11%Si alloys have poor surface roughness in comparison to untreated Al-11%Si alloy. The surface roughness values reduce with cutting speed increment from 70 m/min to 250 m/min. Also, the surface finish deteriorated with increase in feed rate from 0.5 mm/rev to 0.15 mm/rev.


2019 ◽  
Vol 81 (6) ◽  
Author(s):  
Muhammad Yanis ◽  
Amrifan Saladin Mohruni ◽  
Safian Sharif ◽  
Irsyadi Yani

Thin walled titanium alloys are mostly applied in the aerospace industry owing to their favorable characteristic such as high strength-to-weight ratio. Besides vibration, the friction at the cutting zone in milling of thin-walled Ti6Al4V will create inconsistencies in the cutting force and increase the surface roughness. Previous researchers reported the use of vegetable oils in machining metal as an effort towards green machining in reducing the undesirable cutting friction. Machining experiments were conducted under Minimum Quantity Lubrication (MQL) using coconut oil as cutting fluid, which has better oxidative stability than other vegetable oil. Uncoated carbide tools were used in this milling experiment. The influence of cutting speed, feed and depth of cut on cutting force and surface roughness were modeled using response surface methodology (RSM) and artificial neural network (ANN). Experimental machining results indicated that ANN model prediction was more accurate compared to the RSM model. The maximum cutting force and surface roughness values recorded are 14.89 N, and 0.161 µm under machining conditions of 125 m/min cutting speed, 0.04 mm/tooth feed, 0.25 mm radial depth of cut (DOC) and 5 mm axial DOC. 


Author(s):  
R Thirumalai ◽  
JS Senthilkumaar ◽  
P Selvarani ◽  
S Ramesh

Extensive researchers have conducted several experiments in the past for selecting the optimum parameters in machining nickel based alloy – Inconel 718. These experiments conducted so far are dealt with dry machining and flooded coolant machining of nickel alloy Inconel 718. In this research study, the usage of refrigerated coolant is also dealt with and it is compared with dry machining and flooded coolant machining. Cutting speed, feed and depth of cut are considered as the machining parameters. The effectiveness of the refrigerated coolant in machining the heat resistant super alloy material Inconel 718 with respect to these machining parameters are described in this article. The machinability studies parameters were generated with surface roughness and flank wear. The performance of uncoated carbide cutting tool was investigated at various cutting condition under dry, flooded coolant and refrigerated coolant machining. The relationship between the machining parameters and the performance measures were established and using analysis of variance significant machining parameters determined. This article made an attempt to Taguchi optimization technique to study the machinability performances of Inconel 718. Taguchi approach is an efficient and effective experimental method in which a response variable can be optimized, given various control and noise factors, using fewer experiments than a factorial design. Taguchi’s optimization analysis indicates that the factors level, its significance to influence the surface roughness and flank wear for the machining processes. Confirmation tests were conducted at an optimal condition to make a comparison between the experimental results foreseen from the mentioned correlations.


2017 ◽  
Vol 889 ◽  
pp. 152-158
Author(s):  
K. Kadirgama ◽  
K. Abou-El-Hossein

Stainless steel was used for many engineering applications. The optimum parameters needs to be identify to save the cutting tool usage and increase productivity. The purpose of this study is to develop the surface roughness mathematical model for AISI 304 stainless steel when milling using TiN (CVD) carbide tool. The milling process was done under various cutting condition which is cutting speed (1500, 2000 and 2500 rpm), feed rate (0.02, 0.03 and 0.04 mm/tooth) and axial depth (0.1, 0.2 and 0.3 mm). The first order model and quadratic model have been developed using Response Surface Method (RSM) with confident level 95%. The prediction models were comparing with the actual experimental results. It is found that quadratic model much fit the experimental result compare to linear model. In general, the results obtained from the mathematical models were in good agreement with those obtained from the machining experiments. Besides that, it is shown that the influence of cutting speed and feed rate are much higher on surface roughness compare to depth of cut. The optimum cutting speed, feed rate and axial depth is 2500 rpm, 0.0212 mm/tooth and 0.3mm respectively. Besides that, continues chip is produced at cutting speed 2500 rpm meanwhile discontinues chip produced at cutting speed 1500 rpm.


2022 ◽  
pp. 93-102
Author(s):  
Do Duc Trung ◽  
Le Dang Ha

In this article, a study on intermittent surface grinding using aluminum oxide grinding wheel with ceramic binder is presented. The testing material is 20XH3A steel (GOST standard – Russian Federation). The testing sample has been sawn 6 grooves, with the width of each groove of 10 mm, the grooves are evenly distributed on the circumference of sample. The testing sample resembles a splined shaft. An experimental matrix of nine experiments has been built by Taguchi method, in which abrasive grain size, workpiece speed, feed rate and depth of cut were selected as input variables. At each experiment, surface roughness (Ra) and roundness error (RE) have been measured. Experimental results show that the aluminum oxide and ceramic binder grinding wheels are perfectly suitable for grinding intermittent surface of 20XH3A steel. Data Envelopment Analysis based Ranking (DEAR) method has been used to solve the multi-objective optimization problem. The results also showed that in order to simultaneously ensure minimum surface roughness and RE, abrasive grain size is 80 mesh, workpiece speed is 910 rpm, feed rate is 0.05 mm/rev and depth of cut is 0.01 mm. If evaluating the grinding process through two criteria including surface roughness and RE, depth of cut is the parameter having the greatest effect on the grinding process, followed by the influence of feed rate, workpiece speed, and abrasive grain is the parameter having the least effect on the grinding process. In addition, the effect of each input parameter on each output parameter has also been analyzed, and orientations for further works have also been recommended in this article


2013 ◽  
Vol 415 ◽  
pp. 666-671
Author(s):  
Surasit Rawangwong ◽  
Jaknarin Chatthong ◽  
Worapong Boonchouytan

This research study aimed to investigate the effect of main factors on the surface roughness in oil palm wood turning process for manufacturing furniture parts using carbide tools. The main factors, namely, cutting speed, feed rate and depth of cut were investigated for the optimum surface roughness in furniture manufacturing process. The result of preliminary trial shown that the depth of cut had no effect on surface roughness. Moreover, the experiment was found that the factors affecting a surface roughness were cutting speed and feed rate, with having tendency for reduction of roughness value at lower feed rate and greater cutting speed, Therefore in the turning process of oil palm wood, it was possible to determine a cutting condition by means of the equation Ra = 19.8-0.00742 Cutting Speed+3.98 Feed rate, This equation can be best used with limitation of cutting speed at 122-450 m/min, feed rate at 0.1-0.5 mm/rev and depth of cut does not over 1 mm,. To confirm the experiment result, a comparison between the equation value and an actual value by estimating a prediction error value was calculate with the surface roughness and margin of error does not over 10%. The experimental result reveals the mean absolute percentage error (MAPE) of the equation of surface roughness is 3.24%, which is less than the predicted error value and it is acceptable.


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