International Journal of Mechanical Engineering and Technology (IJMET)

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 11, November 2018, pp , Article ID: IJMET_09_11_039 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed EFFECT OF THE ROUGHNESS AND TEMPERATURE OF THE SURFACE OF THE BASE MATERIAL ON THE MECHANICAL PROPERTIES OF THE COATING LAYER (NICKEL - ALUMINUM) SPRAYED THERMALLY BY FLAME Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi Department of Materials Engineering Faculty of Engineering, University of Kufa, Iraq ABSTRACT In this research, the thermal coating process was carried out using flame spraying technique using a gas mixture of oxygen and acetylene for the purpose of obtaining a surface layer of nickel-aluminum (metco450) coating on the surface of medium carbon steel type (AISI 1050) which provide an increase in surface properties and compensation of the base material when lost due to friction or wear. The research was carried out in three successive stages. The first stage included the preparation of the specimens and the design of the base surface of these specimens and Preparation of powder coating and analysis of chemical components for base material and powder coating. The second stage included the implementation of the coating process of (nickel-aluminum) powder by using the flame spray. The coating process was carried out in different ways for each model by changing the different spraying factors, which included the surface roughness of the specimens and the surface temperature of the specimens before the coating process. The third stage of the research included mechanical testing procedures of the coating layer. The tests showed that adhesion increases with increasing surface roughness of the sample prior to coating and the best adhesion is obtained when the base surface of the sample is heated to a temperature of (350 ºC) before the coating process. The resistance of the coating layer to wear is increased with the roughness of the base material surface of the sample due to the increased adhesion of the coating layer and the best resistance to wear when heating the surface of the base material of the sample before coating to temperature (350 ºC). The hardness of the coating layer is increased by increasing the roughness of the surface of the base material of the sample before the coating process and the best surface hardness of the coating layer when heating the surface of the base material of the sample before the coating process to (350 ºC) editor@iaeme.com

2 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi Key words: flame spraying, coating (nickel- aluminum), adhesion, wear resistance, hardness Cite this Article Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi, Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame, International Journal of Mechanical Engineering and Technology, 9(11), 2018, pp INTRODUCTION The definition of thermal spraying according to the ASM is the set of processes that lead to the mineral or non-metallic coating material deposited in a molten or semi-molten state on the surface layer of metals or alloys to form the coating or coating layer [1]. The method of thermal spraying by flame is one of the oldest types of thermal spraying and the most common in the world because of its simplicity and low cost [2]. The thermal spraying by flame uses compressed air or oxygen mixed with a fuel type (ethylene, propylene, propane or hydrogen) to melt and accelerate molten particles [3]. Inert gas such as arcon or nitrogen can be used to emit molten particles if oxidation of the sprayed particles is undesirable [4]. This is due to the relatively low velocity of molten particles (50 m / sec) and relatively low temperatures (approximately 3000 ºC). Coating can be improved by processes called spray and fusion. After spraying, the combustion process is used to increase the temperature of the base material to a degree close to that of the previous melting powder [5]. The result is a very high density coating and high adhesion due to metallurgical bonding between the base material and the coating layer. A wide range of materials can be thermally sprayed in various applications ranging from thermal machine technology (gas turbine) to electrical industries [6]. 2. RESEARCH OBJECTIVES In view of what it represents the thermal spraying by flame of the possibility of obtaining high performance engineering surfaces in a wide range of industrial applications operations, the research aims to: 1) Determine the relationship between the surface roughness of the base material and the mechanical properties of the coating layer by conducting hardness, wear, adhesion and roughness tests for the coating layer. 2) Determine the relationship between the surface temperature of the base material and the mechanical properties of the coating layer by conducting hardness tests, wear, adhesion and roughness of the coating layer. 3) Reduce the losses caused by the failure of the engineering surfaces due to the various types of wear and tear that are exposed to the surfaces of machines with friction or sliding or frequency movements made of Medium carbon steel by spraying with a coating of nickel-aluminum instead of replacing the part. 3. EXPERIMENTAL WORK 3.1 Materials used The materials used include: Medium carbon steel (the base material) A medium carbon steel rod (AISI-1050) was used and cut to obtain the required samples in cylindrical form (mm10 * mm20) and (mm20 * mm10). The component analysis of these samples editor@iaeme.com

3 Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame was carried out in the Materials Engineering Department by Metal analysis device (Portable metals Analyses), Manufactured by ARUN Technology; the results appeared as shown in Table (1). Table 1 Chemical Analysis of Medium Carbon Steel Type (AISI-1050) elements Percentage of elements% elements Percentage of elements% Fe% 97.2 Cr% <0.030 C% Cu% Si% Mo% <0.377 Mn% Ni% Al% <0.020 Ti% <0.020 Co% V% Powder coating used The use of powder coating of (Ni- Al) type (Metco 450) works to generate chemical reactions areas deliberately to enhance the strength of adhesion, heating to a temperature When (1400 ºC) will happen reaction between nickel and aluminum leads to the generation of high temperatures of up to about (3180 ºC) temperature is sufficient to bring about the fusion of the base areas, and be a coating material in the form of the aluminum powder is coated with nickel metal. Table (2) represents the chemical analysis of the powder coating using X-ray machine (X-Ray) type (Twin- X) manufactured by the company (Oxford Instruments). Table 2 Chemical analysis of powder coating (nickel - aluminum) Elements of powder coating( Al-Ni) Percentage of elements% Ni 93 % Al 7 % Table (3) presents the most important characteristics of the powder coating used. Table 3 the characteristics of the powder coating powder coating color Melting point Particle size (nickel - aluminum) gray 1350 ºC 50 µm 3.2 Stages of the implementation of the practical part The implementation of the practical side in three successive stages: The first stage Samples Preparation Stage For the purpose of preparing the samples and preparing their surfaces for thermal spraying using flame, the following is followed: 1- Cutting the steel rod into cylindrical shape and dimensions (20mm*10mm) through cutting and cutting operations with electric saw. 2- Manufacture hardness samples with cylindrical shape and dimensions (10mm*20mm). 3- Making an internal screw tooth in one side of the sample for the purpose of fixing the sample in the sample load axis. 4- Smoothing the outer surface of sample (1) by continuous sanding paper (600, 400, 300, 220 and 120). 5- Increase the roughness of the external surface of the sample (2) by running the sample on the lathe using sandpaper in successive degrees (100, 80, 60, and 40) editor@iaeme.com

4 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi 6- Increase the roughness of the external surface of the sample (3) by running the sample on the lathe using sandpaper (40). Measure the surface roughness of all samples prior to the coating process to be taken as a variable using the roughness device. Three readings were taken for different areas of the sample surface where the roughness was calculated as shown in Table (4). Table 4 the roughness of the samples before coating Surface roughness as measured by (Ra) 0.95 µm 2.65 µm 5.45 µm The second stage Coating Operation Stage The Flam Spray System is designed and implemented in the welding laboratory of the material engineering department using a spray gun. The heat flame is produced by burning oxygen gas and acetylene, which carries the molten powder in the gas mixture stream and attaches to the surface to be coated by the high temperature of the flame which may Up to (3000 ºC). It is necessary to control the pressure of the gases to obtain the flame equal to the speed of the powder rush. The oxygen pressure should be adjusted according to the spray gun used no more than (4 bar) and the acetylene pressure not more than (0.7 bar) before spraying, see Figure (1). Figure 1 Spray gun type (Rototec80) Coating the first group samples The samples of the first group included three samples with different rough surfaces. The samples were tested according to the three methods mentioned above, as shown in Table (4) and the powders were dried in a drying oven to (250 ºC) for (20 minutes). Where the coating process was carried out according to the following sequence: 1. Install the sample on the axis that is associated with the lathe sample. 2. Install the spray gun on the arm directed to the sample and vertically. 3. Cleaning the outside of the sample with a chemical cleaner (Trichloroethylene (C2HCI3)), while avoiding touching the sample after cleaning to prevent contamination with oils and impurities. 4. Rotate the sample at a slow and steady speed during the spraying process editor@iaeme.com

5 Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame 5. The oxygen pressure was set at (3 bar) and the acetylene was pressed on (0.5 bar) of the bottles. The gases were then controlled by the valves in the pistol. The acetylene gas was first opened to ignite the flame and then the oxygen gas was opened. 6. The sample is heated by an oxyacetylene torch to a temperature of (350 ºC) where the temperature is monitored by an infrared thermometer. 7. Conducting a spraying process (nickel-aluminum) from a distance of (250) mm (distance between the spray gun hole and sample surface), It weighed 1.5 g of powder for the cylindrical portion and 0.75 g of base 8. The thickness of the paint bond obtained is up to (0.25) mm. And Figure (2) represents a coated sample. Figure 2 coated sample Coating the second group samples The samples of the second group included three samples with equal surfaces of surface roughness; the sample surface was roughened by the method of roughing the sample (2). The coating process was carried out in the same sequence as the first group samples, except for the process of changing the surface temperature of the sample before spraying the nickel-aluminum coating. Table (5) shows the temperature variables of the sample surface for each sample of the second group. Table (5) the Surface temperature of the samples before coating Surface temperature of sample before coating 150 ºC 350 ºC 550 ºC The third stage Tests stage are: Adhesion test The adhesion of the coating layer was tested by using the tensile test device type (Microcomputer Controlled Electronic Universal Testing Machine (WDW-50E)) was manufactured by (Time Group Inc.) according to (ASTM A370), where adhesion samples were installed in the screw of the tensile device. The test was carried out according to the following steps: 1. Preparation of uncoated samples with equal number of coated samples with dimensions (20mm*10mm). 2. Conduct chemical cleaning by using (Trichloroethylene (C2HCI3)) for both coated and uncoated samples to remove oils and other contaminants that hinder the adhesion of both editor@iaeme.com

6 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi 3. Epoxy adhesive (REP ) was used to paste the two samples together (coated and uncoated). A layer of epoxy is placed on the surface of the coated sample. The coated and uncoated samples are then pressed together for approximately (1 hour) and then dried for (18 hours) at (40 ºC), as shown in Figure (3). Figure 3 shows how to install adhesion samples in tensile jaws device. 4. A vertical load of each sample was applied at a tensile rate (1 mm / min) and until the sample failed, the highest load was recorded. 5. The value of adhesion resistance or cohesion resistance of the coating layer shall be calculated as follows: 6. Two readings were obtained for each sample and their rate was calculated. The value obtained from the test represents the resistance of the weakest part of the system, either in the coating layer itself or at the boundary between the coating layer and the sample surface. The reading value is the adhesion resistance if the failure is in the boundary area between the coating layer and the sample surface while the resistance is the cohesion if the failure occurs within the coating layer itself. 7. The optical microscope was used to determine the location of the failure Wear Test The (pin-on-disk) adhesion wear device was used to test the wear of the coated samples as shown in Figure (4). Figure 4 (pin-on-disk) wear device editor@iaeme.com

7 Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame The rate of wear is calculated by calculating the difference in the weight of the coated sample before and after the test by applying the following law: W.R = W/S.D 1 Where: W.R: Weighted averages wear sliding (gm / mm) W: Weight change is calculated from the following relationship W=W 1-W 2 2 Where W1: Sample weight before test (gm) W2 Sample weight after test (gm) S.D =S*t 3 Where: S.D: represents the slip distance calculated from the following law: S: Sliding speed (cm / min) t: Sliding Time (min) The calculated sliding speed by measuring the small diameter roller (D1) and the large diameter roller (D2) and the radius of rotation of the sample (r) adhesion wear device user. Where: D1=66 mm D2=226mm r=70 mm N motor=950 r.p.m. While the reduction of the rollers ratio is calculated (the velocity) ratio of (i) through the following law: i=d2/d1=226/66=3.424 N1= N motor= 950 r.p.m. Where: N1: The rotational speed of the small reel N2: Rotational speed of the large reel (speed of disc) And always (N1> N2) 3.424=950/N2 N2=277.4 r.p.m. The linear velocity of the disc which is the same as the sliding speed (S). S=(2πN 2/60)*r 4 S=(2π*277.4/60)*0.07=2 m/s=12000cm/min The disc is made of Tool Steel and its hardness (385 HV). Two readings were obtained for each sample and its rate was calculated Hardness test The test was performed using a Brinell hardness device (hardness tester), the use of samples in the shape of a cylindrical disc with dimensions (10mm*20mm) editor@iaeme.com

8 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi The test was carried out as follows: 1. The sample is placed at a distance of 15mm between the test ball and the pressure plate. 2. Place the sample in the test place. 3. The test tool is lowered by turning the wheel manually. 4. The test force is quietly released (9.8 KN) by slowly turning the wheel, 5. As the period of increasing the force to the maximum value should take at least five seconds. 6. Installation of pregnancy for (15s-10s) and then load is lifted. 7. The sample is then raised and the trace diameter is determined on the surface of the coating layer using a microscope, 8. After testing and measuring the trace diameter, as shown in Figure (5), the following law is used to calculate the hardness: HB = 0.102F/0.5πD[D-(D2-d2)] Three readings were obtained for each sample and its rate was calculated. 4. RESULTS AND DISCUSSIONS Figure 5 measuring the trace diameter 4.1 Results of adhesion tests of coating layer and discussion These include the results of adhesion tests for all samples that were coated according to the different variables The results of the surface roughness effect of the sample prior to coating on the adhesion of coating layer Table (6) shows the amount of adhesion of coating layer for each sample of the first group samples, which were coated with varying degrees of the surface roughness of the samples before coating. Table 6 change of adhesion with the degree of roughness of the sample surface before coating Surface roughness as measured by (Ra) 0.95 µm 2.65 µm 5.45 µm Adhesive of coating layer 5.25 MPa 7.85 MPa MPa Figure (6) shows the relationship between the surface roughness of the sample before coating and the amount of adhesion of coating layer. Where there is an increase in adhesion of the coating layer with increased surface roughness of the sample prior to coating due to increased mechanical editor@iaeme.com

9 Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame bonding between the coating and the sample surface resulting from mechanical interlock between the coating and the sample surface protrusions. Adhesive of coating layer MPa Surface roughness as measured by (Ra) µm Figure 6 the relationship between the adhesive of coating layer and degree of the roughness of the sample surface before coating The results of the surface temperature of the sample effect of the sample prior to coating on the adhesion of coating layer Table (7) shows the amount of adhesion of coating layer for each sample of the second group samples, which were coated with varying the surface temperatures of the samples before coating. Table 7 change of adhesion with the surface temperature of the sample before coating Surface temperature of sample before coating 150 ºC 350 ºC 550 ºC Adhesive of coating layer 6.35 MPa 7.95 MPa 7.55 MPa Figure (7) shows the relationship between the sample surface temperature before coating and the amount of adhesion of coating layer, the curve shows that the best adhesion of the coating layer is obtained when the sample surface is heated to a temperature of (350 ºC), The surface heating of the surface prior to the coating process helps these grades to increase the penetration of the coating layer inside the protrusions of the sample surface, While heating to less than (350 ºC) reduces this penetration. Heating to more than (350 ºC) leads to oxidation of the surface of the sample before spraying the coating layer, which leads to the formation of membranes of metal oxide on the surface of the sample, which reduces the adhesion coating layer. Adhesive of coating layer MPa Surface temperature of sample before coating ºC editor@iaeme.com

10 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi Figure 7 the relationship between the adhesive of coating layer and Surface temperature of the sample surface before coating 4.2 Results of wear tests of coating layer and discussion These include the results of wear tests for all samples that were coated according to different variables The results of the surface roughness effect of the sample prior to coating on the rate of wear of coating layer Table (8) shows the rate of wear of coating layer for each sample of the first group samples, which were coated with varying degrees of the surface roughness of the samples before coating. The wear of each sample of the first group was tested at a time of wear (20 minutes) and a vertical force of (5 N). Table 8 change of rate of wear with the degree of roughness of the sample surface before coating Surface roughness as measured by (Ra) 0.95 µm 2.65 µm 5.45 µm Rate of wear 55* * *10-9 (gm/min) (gm/min) (gm/min) Figure (8) shows the relationship between the surface roughness of the sample before coating and the Rate of wear of coating layer. As a result of increasing the overlap of the particles of the coating layer with the surface of the sample composed of roots working on the installation of the coating layer, where with increased surface roughness of the sample before coating increases adhesion and reduce the rate of wear. 60 Rate of wear (*10-9 ) (gm/min) Surface roughness as measured by (Ra) µm Figure 8 the relationship between the rate of wear and degree of the roughness of the sample surface before coating The results of the surface temperature of the sample effect of the sample prior to coating on the rate of wear of coating layer Table (9) shows the rate of wear of coating layer for each sample of the second group samples, which were coated with varying surface temperatures of the samples before coating. The wear of each sample of the first group was tested at a time of wear (20 minutes) and a vertical force of (5 N) editor@iaeme.com

11 Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame Table (9) change of rate of wear with the surface temperature of the sample before coating Surface temperature of sample before coating 150 ºC 350 ºC 550 ºC Rate of wear 40*10-9 (gm/min) 35*10-9 (gm/min) 60*10-9 (gm/min) Figure (9) shows the relationship between the sample surface temperature before coating and the rate of wear of coating layer, The curve shows that the lowest wear rate is obtained when the sample is heated before coating to a temperature of (350 ºC), It is noted that the low surface temperature of (350 ºC) gives a weak bond and high wear rate because the coating layer particles cannot impregnate the surface of the sample, which reduces adhesion strength and increases the rate of wear, A higher surface temperature of more than (350 ºC) leads to oxidation of the surface of the sample before spraying the coating layer, which gives a high wear rate due to the formation of metal oxide membranes on the sample surface preventing adhesion between the sample surface and the coating layer particles. Rate of wear (*10-9 ) (gm/min) Surface temperature of sample before coating ºC Figure 9 the relationship between the rate of wear and surface temperature of sample before coating 4.3 Results of hardness tests of coating layer and discussion These include the results of hardness tests for all samples that were coated according to the different variables The results of the surface roughness effect of the sample prior to coating on the hardness of coating layer Table (10) shows the hardness of coating layer for each sample of the first group samples, which were coated with varying degrees of the surface roughness of the samples before coating. Table 10 change of hardness with the degree of roughness of the sample surface before coating Surface roughness as measured by (Ra) 0.95 µm 2.65 µm 5.45 µm Hardness of coating layer 7*10-3 HB 7.025*10-3 HB 8.055*10-3 HB Figure (10) shows the relationship between the surface roughness of the sample before coating and the hardness of coating layer. Where there is an increase in hardness of the coating layer with increased surface roughness of the sample prior to coating due to increased mechanical editor@iaeme.com

12 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi interlock between the coating and the sample surface protrusions and the coating layer takes extra hardness from the coated sample. Hardness of coating layer (*10-3 ) HB Surface roughness as measured by (Ra) µm Figure 10 the relationship between the hardness and degree of the roughness of the sample surface before coating The results of the surface temperature of the sample effect of the sample prior to coating on the hardness of coating layer Table (11) shows the hardness of coating layer for each sample of the second group samples, which were coated with varying surface temperatures of the samples before coating. Table 11 change of rate of wear with the surface temperature of the sample before coating Surface temperature of sample before coating Hardness of coating layer 150 ºC 350 ºC 550 ºC 6.775*10-3 HB 7.035*10-3 HB 5.525*10-3 HB Figure (11) shows the relationship between the sample surface temperature before coating and the hardness of coating layer, The curve shows that the greatest hardness is obtained when the sample is heated before coating to a temperature of (350 ºC), It is noted that the low surface temperature of (350 ºC) gives a weak bond and low hardness because the coating layer particles cannot impregnate the surface of the sample, which reduces adhesion strength and reduces the hardness while the surface temperature higher than (350 ºC) causes oxidation of the surface of the sample before spraying the coating layer, giving little hardness due to the formation of metallic oxide membranes on the surface of the sample with less hardness as well as reducing the overlap between the coating layer and the sample surface editor@iaeme.com

13 Effect of the Roughness And Temperature of the Surface of the Base Material on the Mechanical Properties of the Coating Layer (Nickel - Aluminum) Sprayed Thermally by Flame Hardness of coating layer (*10-3 ) HB Surface temperature of sample before coating ºC Figure 11 the relationship between the hardness and surface temperature of sample before coating 5. CONCLUSION 1. Increase adhesion of coating layer with increased roughness of the sample surface before coating, it was observed that increasing the roughness of the sample surface prior to coating from (0.95 µm) to (5.45 µm) increased the adhesion of the coating layer from (5.25 MPa) to (11.35 MPa) by about (100%) approximately due to increased mechanical bonding between the coating layer and the sample surface. 2. The best adhesion of the coating layer is obtained when the sample surface is heated before coating to a temperature of (350 ºC), while heating to less than (350 ºC) or more than (350 ºC) reduces the adhesion of coating layer. 3. Increase the wear resistance of the coating layer with increased surface roughness of the sample before coating, It was observed that increasing the surface roughness of the sample prior to coating from (0.95 μm) to (5.45 μm) reduces the rate of wear of the coating layer from (55*10-9 (gm/min)) to (25*10-9 (gm/min)) by about more than half due to increasing the overlap of the particles of the coating layer with the surface of the sample composed of roots working on the installation. 4. The lowest wear rate is obtained when the sample is heated before coating to a temperature of (350 ºC), It is noted that the low surface temperature of (350 ºC) or higher surface temperature of more than (350 ºC) leads to gives a high rate of wear. 5. increase in hardness of the coating layer with increased surface roughness of the sample prior to coating from (0.95 µm) to (5.45 µm) increased the hardness of the coating layer from (7*10-3 HB) to (8.055*10-3 HB) due to increased mechanical interlock between the coating and the sample surface protrusions and the coating layer takes extra hardness from the coated sample. 6. The greatest hardness is obtained when the sample is heated before coating to a temperature of (350 ºC), It is noted that the low surface temperature of (350 ºC) or higher surface temperature of more than (350 ºC) leads to gives a low hardness editor@iaeme.com

14 Ammar Razzaq Hasan, Al-Hadrayi Ziadoon M.R and Ibrahim Joodi Hadi REFERENCES [1] Ammar R.H., 2016, "Effect of change in particle size of the powder coating (Ni- Al) thermally sprayed by flame on the mechanical properties of the coating layer", Muthanna Journal of Engineering and Technology, Vol. (4), No. (1), Pp. (43-50). [2] Soveja A., S. Costil, H. Liao, P. Sallamand, and C.Coddet, 2010, "Remelting of Flame Spraying PEEK Coating Using Lasers", Journal of Thermal Spray Technology, Vol. (19), No. (1-2) Pp. ( ). [3] Vaben R., M. O. Jarligo, T. Steinke, D. E. Mack, D.Stover, 2010, "Overview on advanced thermal barrier coatings, Surface and Coatings Technology", Vol. (205), Pp. ( ). [4] Zhang C., G. Zhang, V. JI, H. Liao, S. Costil, C. Coddet, 2009, "Microstructure and mechanical properties of flame-sprayed PEEK coating remelted by laser process", Progress in Organic Coatings, Vol. (66), Pp. ( ). [5] Ali H. Ataiwi, 2008, "Effect of Some Processing Parameters on Arc Sprayed Coating", Engineering and Technology Journal, University of Technology, Vol. (26), No. (12). [6] Harsha S., D.K. Dwivedi, A. Agrawal, 2007, "Influence of WC addition in Co Cr W Ni C flame sprayed coatings on microstructure, microhardness and wear behavior", Surface and Coatings Technology, Vol. (201), Pp. ( ) editor@iaeme.com