Komgrit Lawanwong - Academia.edu (original) (raw)

Papers by Komgrit Lawanwong

Journal of the Brazilian Society of Mechanical Sciences and Engineering

งานวจยนมจดประสงคเพอเพมความตานทานการสกหรอในแมพมพตดดวยเทคโนโลยการเคลอบผวและการปรบสภาพผว โดยทำการศกษ... more งานวจยนมจดประสงคเพอเพมความตานทานการสกหรอในแมพมพตดดวยเทคโนโลยการเคลอบผวและการปรบสภาพผว โดยทำการศกษาความเสยดทานและการสกหรอโดยวธหมนบอลบนแผนจาน (Ball-on-Disk) ดวยเครองไตรบอมเตอรรวมกบการทำงานปมตดโลหะโดยใชแมพมพตดในการยนยนถงประสทธภาพของฟลมแขงเคลอบผวแมพมพและการปรบสภาพผวเพอสามารถใชเปนแนวทางชวยในการตดสนใจในการเลอกใชชนดของฟลมแขงเคลอบผว โดยวสดทใชทำพนชและบอลเปนเหลกเครองมองานเยนเกรด SKD11 ตามมาตรฐาน JIS ทำการชบแขงทคาความแขง 60±1 HRC. จากนนจงนำไปเคลอบผวและปรบสภาพผวไดแก TiC-CVD (Chemical Vapour Deposition) TiCN-CVD TiCN-PVD (Physical Vapour Deposition) VC-TD (Thermal Diffusion) และไมเคลอบผว ชนงานทใชในการทดลองการตดและแผนจาน เปนเหลกแผนรดเยน SPCC ตามมาตรฐาน JIS หนา 2 มลลเมตร จากการทดลอง พบวาการเคลอบผวหรอปรบสภาพผวชวยลดการสกหรอและคาสมประสทธความเสยดทานได ทงจากการทดลองโดยวธหมนบอลบนแผนจาน (Ball-on-Disk) ดวยเครองไตรบอมเตอร ซงสอดคลองกบผลการปมตด แมพมพทเคลอบผวดวย TiCN-CVD มแนวโนมการลดอตราการสกหรอไดมากกวาผวเคลอบตวอนๆ ซงพบวาเกดจากความแขงแรงในการเกาะยดของฟลม TiCN บนวสดทำแมพมพมคาสงกวาตวอนThe objective of this rese...

内容の要約広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

To reduce springback in U-shape of high strength steel sheet, the present paperproposes a new pro... more To reduce springback in U-shape of high strength steel sheet, the present paperproposes a new process parameter in U-bending technique. This paper aims to present the effect of clearance between die and counterpunch on springback behavior. The process in this work consists of four steps; (1) clamping of a sheet between a punch and a pressure pad, (2) bending with constant clamping force, (3) pushing-up at bottom of the part by using the pressure pad , and (4) final release tool. From the experimental results, decreasing of bending moment by bottom pushing-up resulted in the springback reduction. An appropriate of the clearance between die and pressure pad combined with bottom pushingup force can be reduced springback. Our results suggested that the Y-U model, an advanced kinematic hardening, is essential for accurate numerical simulation of springback behavior.

Introduction.-Cognitive impairment (CI) increases chemotherapy toxicity risk with need to underst... more Introduction.-Cognitive impairment (CI) increases chemotherapy toxicity risk with need to understand this association utilizing publicly available short screening tools. We evaluated this utilizing a lower threshold on a short screening tool in older adults with cancer. Materials and Methods.-We analyzed data from the Cancer and Aging Research Group (CARG) Chemotherapy Toxicity Risk tool (CARG score) development and validation cohorts (n=703), which recruited adults age ≥65 with cancer from academic centers. Cognition was

In this work, the influences of surface coating using TiC, TiCN, TiN, TiAlN film and hard chromiu... more In this work, the influences of surface coating using TiC, TiCN, TiN, TiAlN film and hard chromiumplating and surface treatment by nitriding on the performances of deep drawing operation of stainless steelsheet were investigated. The die material is SKD11 (JIS), and sheet material is SUS304 having thickness of1 mm. The tests were performed by forming the cups having diameter of 40 mm by those coated dies. It hasshown that the die which surface treated by nitriding gave the best results, i.e. giving maximum LDR valuewhich is 4.8% higher than that of the non-coated die and giving the minimum deep drawing force whichleaded to the most uniform wall thickness of the deep-drawn cup. The dies coated with TiC and TiCN filmshowed the potential to prevent an adhesion of the sheet material onto the die surface which is the cause ofgalling on the surface of the products. On the other hands, the die treated by hard chromium tended toincrease the adhesions. Finally, the die coated with TiN and Ti...

Abstract. This research work aims to exploration wear phenomenon on punch for blanking stainless ... more Abstract. This research work aims to exploration wear phenomenon on punch for blanking stainless steel. Three punch materials: JIS SKD11, SKH 51 and SKS 3 were studied. Those punches were hardened to fixed hardness 59 HRC. Stainless steel JIS SUS 430 having the same thickness of 2 mm were employed as workpiece material for the experiments. Clearance between punch and die of blanking tool was five percent of workpiece thickness. The strip was blanked into circular shapes of 25 mm. in diameter. Direct measurement of wear on blanking punch was carried out using optical microscope. Each punch was used for blanking 2,000 stroke/conditions. It was found that SKH 51 had shown lower wear than SK D 11 and SKS 3 respectively. The higher tungsten, molybdenum and vanadium content of SKH 51 increase the amount of carbide compound caused hard and durable of cutting edge. Beside, punch SKD 11 had shown highest adhesive because high chromium content has compatibility of elements. The compatibility ...

The International Journal of Advanced Manufacturing Technology

Key Engineering Materials

In recent years, warm forming of magnesium sheets has been investigated by many researchers since... more In recent years, warm forming of magnesium sheets has been investigated by many researchers since the ductility of the sheets becomes considerably higher due to low CRSS (critical resolved shear stress) at high temperatures (e.g., [1]-[3]). In the present research, the springback of AZ31 magnesium sheet was investigated by performing a draw-bending experiment at several temperatures from 20 °C (room temperature) to 200 °C at drawing speeds ranging from 0.01 to 1.0 mm/s. From the experiment, it was found that the springback was remarkably reduced at 200 °C, especially at a low forming speed, since the flow stress was very low under such a forming condition, and furthermore, the stress relaxation effect was dominant. The effects of temperature and forming speed on springback were discussed.

Materials Science Forum

The hole expansion process is a forming process that the fracture easily occurred on the hole edg... more The hole expansion process is a forming process that the fracture easily occurred on the hole edge. Therefore, many research papers presented various processes to make a precision pre-hole shearing to a hole expansion process such as wire cut, EDM, and laser cut. The purpose of this work is to increase a hole expansion ratio on the high strength steel sheet. The conventional piercing by piercing punch and piercing with a counter punch was used to make a pre-hole shearing process in this research paper. The high strength steel grade 590 and 980 MPa of 1.2 mm of thickness were used in the experiments. From experimental results, it was found that the pre-hole shearing by piercing with a counter punch can be increased a shear surface on cutting edge of workpiece. Moreover, the used piercing with counter punch can improve the hole expansion ratio more than the conventional piercing process because sheared surface around the hole edge was increased.

Materials Science Forum

To reduce springback in U-shape of high strength steel sheet, the present paper proposes a new pr... more To reduce springback in U-shape of high strength steel sheet, the present paper proposes a new process parameter in U-bending technique. This paper aims to present the effect of clearance between die and pressure pad on springback behavior. The process in this work consists of four steps: (1) clamping of a sheet between a punch and a pressure pad, (2) bending with constant clamping force, (3) pushing-up at bottom of the part by using the pressure pad, and (4) final release tool. From the experimental results, decreasing of bending moment by bottom pushing-up resulted in the springback reduction. An appropriate of the clearance between die and pressure pad combined with bottom pushing-up force can be reduced springback. Our results suggested that the Y-U model, an advanced kinematic hardening, is essential for accurate numerical simulation of springback behavior.

Key Engineering Materials, 2016

Tool steel grade JIS; SKD-11 is a well-known raw material for making a high wear resistance of bl... more Tool steel grade JIS; SKD-11 is a well-known raw material for making a high wear resistance of blanking tool in stamping industry. One problem in the blanking process is the high cost of raw material for making punch and die. Therefore, in this study, behavior of wear phenomenon and ability of recycle on the punch of blanking die process were investigated. In the first section, phenomenon and mechanism wear of blanking punch were observed. We found that mechanism of wear on blanking punch was adhesion wear, since high amount of chromium content in the punch has compatibility of elements. The second section, recovery punch was designed by annealing, resize and quenching process by using the new punch from the first section. From the recovery punch results, it was found that the wear resistance of recovery punch decreased slightly but it was strong enough to continue in blanking process. However, the recycle process of tool steel depends on a quality and amount of the product.

วารสารวิจัยและพัฒนา มจธ, 2007

Advanced Materials Research, 2011

Bending process is an important process in the metal sheet forming in many industries. The main p... more Bending process is an important process in the metal sheet forming in many industries. The main problem of the bending process is the spring-back phenomenon after removing the punch. This research aims the investigation on effect of residual stress on springback behavior of sheet metal in U bending process. The corner setting technique and bottoming process were designed for experiments. The corner setting technique and bottoming has reduced the thickness in bending area to 5, 10, 15 and 20 percent of the original sheet thickness. Clearance between punch and die of both processes was equal to same the thickness. The residual stress value and springback phenomenal were investigated by commercial program code DEFORM 2D which was able to analyze the effect stress and force in bending area. Electrolytic zinc coated carbon steel grade JIS; SECC, JIS; 440 and JIS; 590 which having the thickness of 1 mm were employed as the workpiece material for all experiments. The result of three materi...

Advanced Materials Research, 2014

To reduce springback in U-bending the present paper proposes a new technique where the bottom of ... more To reduce springback in U-bending the present paper proposes a new technique where the bottom of a U-bent part is clamped between a punch and a counter-punch during bending and it is pushed up with the counter punch at the final stage. The effect of counter punch pressure, both in sheet clamping and bottoming, was investigated by performing experiments on dual phase 590MPa and TRIP 780MPa HSS sheets. From the experiment, an appropriate combination of the clamping force and the final pushing-up force was found where springback was reduced to almost zero. To investigate the mechanism of the reduction of springback in the above three-step U-bending process, FE simulation of the bending with PAM-STAMP 2G was also conducted where the advanced kinematic hardening Yoshida-Uemori model was employed.

2010 2nd International Conference on Mechanical and Electronics Engineering, 2010

Abstract Bending process is an important process in the sheet metal forming in many industries. T... more Abstract Bending process is an important process in the sheet metal forming in many industries. The main problem of the bending process is spring-back phenomenon after removing the punch. This research aims to reduce spring-back value of sheet metal in U ...

Advanced Materials Research, 2011

Anisotropic behaviors of high strength steel grade SPFH590 and HPFC780 used extensively in automo... more Anisotropic behaviors of high strength steel grade SPFH590 and HPFC780 used extensively in automotive industry are explored. V-bending tests were carried out on various bending direction. It was found that the investigated material showed little differences in the resistance to deformation and resistance to thinning from all directions. Thereafter, negligible effect of the bending direction on the degree of springback was detected. Large bend radius caused high level of springback. However, the increasing rate of springback is decreased with larger radius.

International Journal of Abrasive Technology, 2009

ABSTRACT The non-coated ball (SKD11; hardness 60 ± 2 HRC), balls coated with TiC-CVD, TiAlN-PVD, ... more ABSTRACT The non-coated ball (SKD11; hardness 60 ± 2 HRC), balls coated with TiC-CVD, TiAlN-PVD, TiCN-CVD, TiCN-PVD and ball treated by VC-TD (thermal diffusion) have been evaluated in sliding contact against the disk which was made from automobile structural steel grade SAPH 440 and high strength steel grade SPFH 590. It was found that non-coated ball showed maximum specific wear rate and TiCN-CVD coated ball exhibited minimum specific wear rate. The effectiveness of hard thin film coated tool in metal stamping process is also investigated by performing U-bending experiment. In the case of non-coated tool, the result showed that adhesion of workpiece material on a die face was detected after 49 strokes for SPFH 590 steel. Whereas no adhesion was found on the tool coated with TiCN-CVD after 500 strokes. In order to understand the phenomenon, scratch tests were done on each type of coated tool to characterise the adhesion strength.

Applied Mechanics and Materials, 2012

This research aims to investigate the types of thin film coating for the evaluation of coefficien... more This research aims to investigate the types of thin film coating for the evaluation of coefficient of friction using ring compression test. Ring compression test was used to evaluate the coefficient of friction of contact between die coating surface and workpiece material, brass grade C3771. Specimen was machined by CNC to the standard size with ratio of the outer diameter [25.4mm] to inner diameter [12.7mm] and thickness [8.5 mm] is 6:3:2. The dies were made from tool steel grade JIS SKD11 hardened to 60±2HRC then polished die surface at Ra= 0:07 to0:09 microns. Tool surface conditions selected for this research were non-coated, PVD coated DLC, AlCrN, TiCN and TiAlN.The Experiments were carried without lubricant. Experiments were reduced height of the specimen at 50 percent. It was found that Non coated condition had shown lower coefficient of friction than DLC, AlCrN, TiAlN and TiCN due to influence of surface roughness. Furthermore, thin film coated die had shown durable and high...

Journal of the Brazilian Society of Mechanical Sciences and Engineering

งานวจยนมจดประสงคเพอเพมความตานทานการสกหรอในแมพมพตดดวยเทคโนโลยการเคลอบผวและการปรบสภาพผว โดยทำการศกษ... more งานวจยนมจดประสงคเพอเพมความตานทานการสกหรอในแมพมพตดดวยเทคโนโลยการเคลอบผวและการปรบสภาพผว โดยทำการศกษาความเสยดทานและการสกหรอโดยวธหมนบอลบนแผนจาน (Ball-on-Disk) ดวยเครองไตรบอมเตอรรวมกบการทำงานปมตดโลหะโดยใชแมพมพตดในการยนยนถงประสทธภาพของฟลมแขงเคลอบผวแมพมพและการปรบสภาพผวเพอสามารถใชเปนแนวทางชวยในการตดสนใจในการเลอกใชชนดของฟลมแขงเคลอบผว โดยวสดทใชทำพนชและบอลเปนเหลกเครองมองานเยนเกรด SKD11 ตามมาตรฐาน JIS ทำการชบแขงทคาความแขง 60±1 HRC. จากนนจงนำไปเคลอบผวและปรบสภาพผวไดแก TiC-CVD (Chemical Vapour Deposition) TiCN-CVD TiCN-PVD (Physical Vapour Deposition) VC-TD (Thermal Diffusion) และไมเคลอบผว ชนงานทใชในการทดลองการตดและแผนจาน เปนเหลกแผนรดเยน SPCC ตามมาตรฐาน JIS หนา 2 มลลเมตร จากการทดลอง พบวาการเคลอบผวหรอปรบสภาพผวชวยลดการสกหรอและคาสมประสทธความเสยดทานได ทงจากการทดลองโดยวธหมนบอลบนแผนจาน (Ball-on-Disk) ดวยเครองไตรบอมเตอร ซงสอดคลองกบผลการปมตด แมพมพทเคลอบผวดวย TiCN-CVD มแนวโนมการลดอตราการสกหรอไดมากกวาผวเคลอบตวอนๆ ซงพบวาเกดจากความแขงแรงในการเกาะยดของฟลม TiCN บนวสดทำแมพมพมคาสงกวาตวอนThe objective of this rese...

内容の要約広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

To reduce springback in U-shape of high strength steel sheet, the present paperproposes a new pro... more To reduce springback in U-shape of high strength steel sheet, the present paperproposes a new process parameter in U-bending technique. This paper aims to present the effect of clearance between die and counterpunch on springback behavior. The process in this work consists of four steps; (1) clamping of a sheet between a punch and a pressure pad, (2) bending with constant clamping force, (3) pushing-up at bottom of the part by using the pressure pad , and (4) final release tool. From the experimental results, decreasing of bending moment by bottom pushing-up resulted in the springback reduction. An appropriate of the clearance between die and pressure pad combined with bottom pushingup force can be reduced springback. Our results suggested that the Y-U model, an advanced kinematic hardening, is essential for accurate numerical simulation of springback behavior.

Introduction.-Cognitive impairment (CI) increases chemotherapy toxicity risk with need to underst... more Introduction.-Cognitive impairment (CI) increases chemotherapy toxicity risk with need to understand this association utilizing publicly available short screening tools. We evaluated this utilizing a lower threshold on a short screening tool in older adults with cancer. Materials and Methods.-We analyzed data from the Cancer and Aging Research Group (CARG) Chemotherapy Toxicity Risk tool (CARG score) development and validation cohorts (n=703), which recruited adults age ≥65 with cancer from academic centers. Cognition was

In this work, the influences of surface coating using TiC, TiCN, TiN, TiAlN film and hard chromiu... more In this work, the influences of surface coating using TiC, TiCN, TiN, TiAlN film and hard chromiumplating and surface treatment by nitriding on the performances of deep drawing operation of stainless steelsheet were investigated. The die material is SKD11 (JIS), and sheet material is SUS304 having thickness of1 mm. The tests were performed by forming the cups having diameter of 40 mm by those coated dies. It hasshown that the die which surface treated by nitriding gave the best results, i.e. giving maximum LDR valuewhich is 4.8% higher than that of the non-coated die and giving the minimum deep drawing force whichleaded to the most uniform wall thickness of the deep-drawn cup. The dies coated with TiC and TiCN filmshowed the potential to prevent an adhesion of the sheet material onto the die surface which is the cause ofgalling on the surface of the products. On the other hands, the die treated by hard chromium tended toincrease the adhesions. Finally, the die coated with TiN and Ti...

Abstract. This research work aims to exploration wear phenomenon on punch for blanking stainless ... more Abstract. This research work aims to exploration wear phenomenon on punch for blanking stainless steel. Three punch materials: JIS SKD11, SKH 51 and SKS 3 were studied. Those punches were hardened to fixed hardness 59 HRC. Stainless steel JIS SUS 430 having the same thickness of 2 mm were employed as workpiece material for the experiments. Clearance between punch and die of blanking tool was five percent of workpiece thickness. The strip was blanked into circular shapes of 25 mm. in diameter. Direct measurement of wear on blanking punch was carried out using optical microscope. Each punch was used for blanking 2,000 stroke/conditions. It was found that SKH 51 had shown lower wear than SK D 11 and SKS 3 respectively. The higher tungsten, molybdenum and vanadium content of SKH 51 increase the amount of carbide compound caused hard and durable of cutting edge. Beside, punch SKD 11 had shown highest adhesive because high chromium content has compatibility of elements. The compatibility ...

The International Journal of Advanced Manufacturing Technology

Key Engineering Materials

In recent years, warm forming of magnesium sheets has been investigated by many researchers since... more In recent years, warm forming of magnesium sheets has been investigated by many researchers since the ductility of the sheets becomes considerably higher due to low CRSS (critical resolved shear stress) at high temperatures (e.g., [1]-[3]). In the present research, the springback of AZ31 magnesium sheet was investigated by performing a draw-bending experiment at several temperatures from 20 °C (room temperature) to 200 °C at drawing speeds ranging from 0.01 to 1.0 mm/s. From the experiment, it was found that the springback was remarkably reduced at 200 °C, especially at a low forming speed, since the flow stress was very low under such a forming condition, and furthermore, the stress relaxation effect was dominant. The effects of temperature and forming speed on springback were discussed.

Materials Science Forum

The hole expansion process is a forming process that the fracture easily occurred on the hole edg... more The hole expansion process is a forming process that the fracture easily occurred on the hole edge. Therefore, many research papers presented various processes to make a precision pre-hole shearing to a hole expansion process such as wire cut, EDM, and laser cut. The purpose of this work is to increase a hole expansion ratio on the high strength steel sheet. The conventional piercing by piercing punch and piercing with a counter punch was used to make a pre-hole shearing process in this research paper. The high strength steel grade 590 and 980 MPa of 1.2 mm of thickness were used in the experiments. From experimental results, it was found that the pre-hole shearing by piercing with a counter punch can be increased a shear surface on cutting edge of workpiece. Moreover, the used piercing with counter punch can improve the hole expansion ratio more than the conventional piercing process because sheared surface around the hole edge was increased.

Materials Science Forum

To reduce springback in U-shape of high strength steel sheet, the present paper proposes a new pr... more To reduce springback in U-shape of high strength steel sheet, the present paper proposes a new process parameter in U-bending technique. This paper aims to present the effect of clearance between die and pressure pad on springback behavior. The process in this work consists of four steps: (1) clamping of a sheet between a punch and a pressure pad, (2) bending with constant clamping force, (3) pushing-up at bottom of the part by using the pressure pad, and (4) final release tool. From the experimental results, decreasing of bending moment by bottom pushing-up resulted in the springback reduction. An appropriate of the clearance between die and pressure pad combined with bottom pushing-up force can be reduced springback. Our results suggested that the Y-U model, an advanced kinematic hardening, is essential for accurate numerical simulation of springback behavior.

Key Engineering Materials, 2016

Tool steel grade JIS; SKD-11 is a well-known raw material for making a high wear resistance of bl... more Tool steel grade JIS; SKD-11 is a well-known raw material for making a high wear resistance of blanking tool in stamping industry. One problem in the blanking process is the high cost of raw material for making punch and die. Therefore, in this study, behavior of wear phenomenon and ability of recycle on the punch of blanking die process were investigated. In the first section, phenomenon and mechanism wear of blanking punch were observed. We found that mechanism of wear on blanking punch was adhesion wear, since high amount of chromium content in the punch has compatibility of elements. The second section, recovery punch was designed by annealing, resize and quenching process by using the new punch from the first section. From the recovery punch results, it was found that the wear resistance of recovery punch decreased slightly but it was strong enough to continue in blanking process. However, the recycle process of tool steel depends on a quality and amount of the product.

วารสารวิจัยและพัฒนา มจธ, 2007

Advanced Materials Research, 2011

Bending process is an important process in the metal sheet forming in many industries. The main p... more Bending process is an important process in the metal sheet forming in many industries. The main problem of the bending process is the spring-back phenomenon after removing the punch. This research aims the investigation on effect of residual stress on springback behavior of sheet metal in U bending process. The corner setting technique and bottoming process were designed for experiments. The corner setting technique and bottoming has reduced the thickness in bending area to 5, 10, 15 and 20 percent of the original sheet thickness. Clearance between punch and die of both processes was equal to same the thickness. The residual stress value and springback phenomenal were investigated by commercial program code DEFORM 2D which was able to analyze the effect stress and force in bending area. Electrolytic zinc coated carbon steel grade JIS; SECC, JIS; 440 and JIS; 590 which having the thickness of 1 mm were employed as the workpiece material for all experiments. The result of three materi...

Advanced Materials Research, 2014

To reduce springback in U-bending the present paper proposes a new technique where the bottom of ... more To reduce springback in U-bending the present paper proposes a new technique where the bottom of a U-bent part is clamped between a punch and a counter-punch during bending and it is pushed up with the counter punch at the final stage. The effect of counter punch pressure, both in sheet clamping and bottoming, was investigated by performing experiments on dual phase 590MPa and TRIP 780MPa HSS sheets. From the experiment, an appropriate combination of the clamping force and the final pushing-up force was found where springback was reduced to almost zero. To investigate the mechanism of the reduction of springback in the above three-step U-bending process, FE simulation of the bending with PAM-STAMP 2G was also conducted where the advanced kinematic hardening Yoshida-Uemori model was employed.

2010 2nd International Conference on Mechanical and Electronics Engineering, 2010

Abstract Bending process is an important process in the sheet metal forming in many industries. T... more Abstract Bending process is an important process in the sheet metal forming in many industries. The main problem of the bending process is spring-back phenomenon after removing the punch. This research aims to reduce spring-back value of sheet metal in U ...

Advanced Materials Research, 2011

Anisotropic behaviors of high strength steel grade SPFH590 and HPFC780 used extensively in automo... more Anisotropic behaviors of high strength steel grade SPFH590 and HPFC780 used extensively in automotive industry are explored. V-bending tests were carried out on various bending direction. It was found that the investigated material showed little differences in the resistance to deformation and resistance to thinning from all directions. Thereafter, negligible effect of the bending direction on the degree of springback was detected. Large bend radius caused high level of springback. However, the increasing rate of springback is decreased with larger radius.

International Journal of Abrasive Technology, 2009

ABSTRACT The non-coated ball (SKD11; hardness 60 ± 2 HRC), balls coated with TiC-CVD, TiAlN-PVD, ... more ABSTRACT The non-coated ball (SKD11; hardness 60 ± 2 HRC), balls coated with TiC-CVD, TiAlN-PVD, TiCN-CVD, TiCN-PVD and ball treated by VC-TD (thermal diffusion) have been evaluated in sliding contact against the disk which was made from automobile structural steel grade SAPH 440 and high strength steel grade SPFH 590. It was found that non-coated ball showed maximum specific wear rate and TiCN-CVD coated ball exhibited minimum specific wear rate. The effectiveness of hard thin film coated tool in metal stamping process is also investigated by performing U-bending experiment. In the case of non-coated tool, the result showed that adhesion of workpiece material on a die face was detected after 49 strokes for SPFH 590 steel. Whereas no adhesion was found on the tool coated with TiCN-CVD after 500 strokes. In order to understand the phenomenon, scratch tests were done on each type of coated tool to characterise the adhesion strength.

Applied Mechanics and Materials, 2012

This research aims to investigate the types of thin film coating for the evaluation of coefficien... more This research aims to investigate the types of thin film coating for the evaluation of coefficient of friction using ring compression test. Ring compression test was used to evaluate the coefficient of friction of contact between die coating surface and workpiece material, brass grade C3771. Specimen was machined by CNC to the standard size with ratio of the outer diameter [25.4mm] to inner diameter [12.7mm] and thickness [8.5 mm] is 6:3:2. The dies were made from tool steel grade JIS SKD11 hardened to 60±2HRC then polished die surface at Ra= 0:07 to0:09 microns. Tool surface conditions selected for this research were non-coated, PVD coated DLC, AlCrN, TiCN and TiAlN.The Experiments were carried without lubricant. Experiments were reduced height of the specimen at 50 percent. It was found that Non coated condition had shown lower coefficient of friction than DLC, AlCrN, TiAlN and TiCN due to influence of surface roughness. Furthermore, thin film coated die had shown durable and high...