MB Karamış - Academia.edu (original) (raw)

Papers by MB Karamış

IOP Conference Series: Materials Science and Engineering, 2018

In this study mechanichal and tribological properties of keratin, bone ash and hydroxylapatite by... more In this study mechanichal and tribological properties of keratin, bone ash and hydroxylapatite by adding to PMMA ( known as the main prosthesis material) were investigated. Hydroxylapatite, bone ash, and keratin materials were added as PMMA in to the content of PMMA, in the proportions of %1, %3 and %5, respectively. The resulting mixtures were put into the molds and solidified in order to obtain samples to be used in the wear experiments. Each experiment was conducted by preparing three experimental samples. The wear data were compared according to the average values of the experimental samples. In the wear test, the results were also evaluated according to the average values obtained from each group and the results of the control group. It was observed that, the wear resistance of the PMMA including 3%, 5% bone ash and PMMA including 5% keratin flour were higher than the values of the control group.

IOP Conference Series: Materials Science and Engineering, 2018

Materials Science and Technology, 2012

The reciprocating extrusion (RE) method was developed to fabricate the fine grain AA 6061 and AA ... more The reciprocating extrusion (RE) method was developed to fabricate the fine grain AA 6061 and AA 6063 alloys and to obtain their optimum mechanical properties. While 6061/72 mm aluminium alloy powder and AA 6063 bar material were used as a matrix material separately, SiC/20 mm ceramic particles were used as reinforcement. Billets were produced from AA 6061 powders and AA 6063 materials mixed with SiC ceramic particles by sintering and stir casting method respectively. Using the RE process, which was performed at 573 K for one, five and nine passes, the billets were extruded again to investigate the microcharacterisation of the products. The hardness, microstructure, grain size and distribution of the extruded samples were examined and analysed using an SEM. High resolution electron backscatter diffraction and TEM methods were also applied for grain analysis. The manufacturing method of the billets to be extruded reciprocatively affects the hardness that occurs after the deformation. The hardnesses of all samples increase first and then decrease with pass number. After extrusion passes, the longer or larger silicon particles were broken into finer particles and microstructures were changed from the initial to a new structure. A homogeneous distribution of SiCp and refined grain structure of the test materials were obtained by RE. However, the process temperature applied during the process has a greater effect on the change in grain size than that of the occurring deformation.

Wear, 2012

ABSTRACT In this study, a number of metal matrix composites were manufactured to determine their ... more ABSTRACT In this study, a number of metal matrix composites were manufactured to determine their tribological properties. AA2124 matrix material, reinforced by SiC, B4C or Al2O3 (of different particle sizes), was used for manufacturing by powder metallurgy. The reinforcing particles were included at 10%, 20% and 30% volume fraction (vf). The matrix and reinforcement powders were compressed at 600 MPa and 615 °C for 30 min in an argon atmosphere. For comparison with the metal matrix composites (MMC), unreinforced AA2124 samples and GGG40 cam material samples (both induction-hardened and untreated) were also prepared for tribological tests. Tribological tests were conducted at 50 N loading with 900 rpm revolution for 30 min under dry conditions.The specific wear rates of the composites reinforced with 10% volume fraction of B4C or SiC are each lower than that of the GGG40 cam material. While the composite having 30% volume fraction of 20 μm SiC gives the best wear performance, the sample with B4C shows the best performance at 10% vf.

Wear, 2006

The erosion behaviours of the nodular and gray cast irons were studied at an intermediate and nor... more The erosion behaviours of the nodular and gray cast irons were studied at an intermediate and normal impact angles via an experimental setup. Erosion tests were carried out at impact angles of 30 • , 60 • and 90 • using angular hard particles. The particle velocity was controlled utilizing the gas pressure and was measured with rotating double discs. The results showed considerable weight loss variation as a function of the impact angles. The highest erosion rate occurred at an impact angle of 30 • and then, two types of the cast irons exhibited the least resistance to erosion. While the rate was at an intermediate level at 60 • , the lowest rate occurred at normal impact angle. It was found that the erosion rate of the nodular cast iron (NCI) was lower than that of the gray cast iron (GCI) at all impact angles. In all cases, the erosion appeared to have occurred by a ductile process. At oblique impact angles (30 • and 60 •), hard erodent caused plastic flow in relatively softer surface of nodular cast iron and material removal occurred by microcutting and microploughing. During the erosive wear progress for nodular cast iron, just below the eroded surface, even though the ends of which behaved as crack nucleation agents, the deformed graphite fines were not broken off from the surface in a short time. No remarkable changes were relatively observed in the wear mechanisms. At a normal impact angle, material loss from the nodular cast iron surface occurred via gauging. Deformation spreading was also observed beneath the surface under at all impact tests. As far as gray cast iron is considered, the erodent can cause plastic yielding in the target surface and material removal went on by major ploughing with microcracking and subsurface fatigue. At a normal impact angle, the erosive wear occurred by chipping and small-scale fracture.

Materials Science and Engineering: A, 2010

In this study, two surface processes, TIG surface melting and chilling, were applied to remove th... more In this study, two surface processes, TIG surface melting and chilling, were applied to remove the negative effect of the near-surface graphite phases of nodular cast iron. Afterwards, the treated surfaces were plasma-nitrided and boronized. After graphite elimination processes, plasma nitriding and boronizing, the microstructures were compared with the one of untreated cast iron. The results showed that the chilling process that was applied during the casting process of nodular cast iron did not eliminate the graphite phases from the surface. However, an almost nodule-free surface was obtained by the TIG melting process. It was of no use in nitriding and boronizing the chilled surfaces due to the existence of superficial nodular graphite in the surfaces after completion of the chilling. On the other hand, a continuous uninterrupted compound layer and boride layer were observed on the TIG melted surface. Under the light of these experimental studies, the TIG surface process is proposed to eliminate the nodular graphite on flat and curved surfaces of nodular cast iron parts before thermochemical surface hardening treatments or hard coating processes are applied to the nodular cast iron surfaces.

Journal of Materials Processing Technology, 2003

... References. [1] MB Karamış and R. İpek, An evaluation of possibilities of the carbonitride si... more ... References. [1] MB Karamış and R. İpek, An evaluation of possibilities of the carbonitride simple steels instead of carburized low alloy steels (wear properties). Appl. Surf. Sci., 119 (1997), pp. 25–33. [2] JL Arques and JM Prado, The dry wear resistance of a carbonitrided steel. ...

Journal of Materials Processing Technology, 2003

In this study, ISO Cu-DHP tubes were brazed using different filler metals such as AWS BCuP-2, BCu... more In this study, ISO Cu-DHP tubes were brazed using different filler metals such as AWS BCuP-2, BCuP-3, BCuP-5, BAg-16, and DIN L-CuP7 and L-Ag40Cd. The microstructures of the brazed zone of tubes were examined with optical and scanning electron microscopic studies. Hardness measurement and leak-tight tests were conducted. The discontinuities in the brazed zone were determined. The microstructures of the

Wear, 2005

The wear behaviour of the Al-Mo-Ni coating on piston ring material against gray cast iron was inv... more The wear behaviour of the Al-Mo-Ni coating on piston ring material against gray cast iron was investigated under dry and lubricated conditions at elevated temperatures. AISI 440C steel material, widely used in manufacturing piston ring for two-cycle engines, was coated by plasma spraying method including Al-Mo-Ni powders. Wear tests were carried out on a universal wear tester with a loading of 83, 100, 200 and 300 N, and at elevated temperatures of 25, 100, 200 and 300 • C under dry and lubricated conditions. In conclusion, the material loss of the Al-Mo-Ni composite coating is increased with elevated temperatures under dry and lubricated sliding conditions. The material loss is sharply increased up to temperature point of 100 • C under dry sliding condition while it is nearly constant after this point with test loading of 100 N. Under lubricated conditions, the same tendency can be obtained for loading of 83 N. The wear mechanism is mixed mode such as abrasion, scuffing, delamination for dry conditions. Under lubricated conditions, for the lower temperature, the absorbed oil inclusions in the porosities postpone the wear in progress, resulting in easy friction. The wear mechanism of Al-Mo-Ni coating is predominantly abrasive, and delamination also occurs under heavy loading. The wear of the coating under lubricated conditions is nearly 10 times lower than that of dry conditions.

IOP Conference Series: Materials Science and Engineering, 2018

In this study mechanichal and tribological properties of keratin, bone ash and hydroxylapatite by... more In this study mechanichal and tribological properties of keratin, bone ash and hydroxylapatite by adding to PMMA ( known as the main prosthesis material) were investigated. Hydroxylapatite, bone ash, and keratin materials were added as PMMA in to the content of PMMA, in the proportions of %1, %3 and %5, respectively. The resulting mixtures were put into the molds and solidified in order to obtain samples to be used in the wear experiments. Each experiment was conducted by preparing three experimental samples. The wear data were compared according to the average values of the experimental samples. In the wear test, the results were also evaluated according to the average values obtained from each group and the results of the control group. It was observed that, the wear resistance of the PMMA including 3%, 5% bone ash and PMMA including 5% keratin flour were higher than the values of the control group.

IOP Conference Series: Materials Science and Engineering, 2018

Materials Science and Technology, 2012

The reciprocating extrusion (RE) method was developed to fabricate the fine grain AA 6061 and AA ... more The reciprocating extrusion (RE) method was developed to fabricate the fine grain AA 6061 and AA 6063 alloys and to obtain their optimum mechanical properties. While 6061/72 mm aluminium alloy powder and AA 6063 bar material were used as a matrix material separately, SiC/20 mm ceramic particles were used as reinforcement. Billets were produced from AA 6061 powders and AA 6063 materials mixed with SiC ceramic particles by sintering and stir casting method respectively. Using the RE process, which was performed at 573 K for one, five and nine passes, the billets were extruded again to investigate the microcharacterisation of the products. The hardness, microstructure, grain size and distribution of the extruded samples were examined and analysed using an SEM. High resolution electron backscatter diffraction and TEM methods were also applied for grain analysis. The manufacturing method of the billets to be extruded reciprocatively affects the hardness that occurs after the deformation. The hardnesses of all samples increase first and then decrease with pass number. After extrusion passes, the longer or larger silicon particles were broken into finer particles and microstructures were changed from the initial to a new structure. A homogeneous distribution of SiCp and refined grain structure of the test materials were obtained by RE. However, the process temperature applied during the process has a greater effect on the change in grain size than that of the occurring deformation.

Wear, 2012

ABSTRACT In this study, a number of metal matrix composites were manufactured to determine their ... more ABSTRACT In this study, a number of metal matrix composites were manufactured to determine their tribological properties. AA2124 matrix material, reinforced by SiC, B4C or Al2O3 (of different particle sizes), was used for manufacturing by powder metallurgy. The reinforcing particles were included at 10%, 20% and 30% volume fraction (vf). The matrix and reinforcement powders were compressed at 600 MPa and 615 °C for 30 min in an argon atmosphere. For comparison with the metal matrix composites (MMC), unreinforced AA2124 samples and GGG40 cam material samples (both induction-hardened and untreated) were also prepared for tribological tests. Tribological tests were conducted at 50 N loading with 900 rpm revolution for 30 min under dry conditions.The specific wear rates of the composites reinforced with 10% volume fraction of B4C or SiC are each lower than that of the GGG40 cam material. While the composite having 30% volume fraction of 20 μm SiC gives the best wear performance, the sample with B4C shows the best performance at 10% vf.

Wear, 2006

The erosion behaviours of the nodular and gray cast irons were studied at an intermediate and nor... more The erosion behaviours of the nodular and gray cast irons were studied at an intermediate and normal impact angles via an experimental setup. Erosion tests were carried out at impact angles of 30 • , 60 • and 90 • using angular hard particles. The particle velocity was controlled utilizing the gas pressure and was measured with rotating double discs. The results showed considerable weight loss variation as a function of the impact angles. The highest erosion rate occurred at an impact angle of 30 • and then, two types of the cast irons exhibited the least resistance to erosion. While the rate was at an intermediate level at 60 • , the lowest rate occurred at normal impact angle. It was found that the erosion rate of the nodular cast iron (NCI) was lower than that of the gray cast iron (GCI) at all impact angles. In all cases, the erosion appeared to have occurred by a ductile process. At oblique impact angles (30 • and 60 •), hard erodent caused plastic flow in relatively softer surface of nodular cast iron and material removal occurred by microcutting and microploughing. During the erosive wear progress for nodular cast iron, just below the eroded surface, even though the ends of which behaved as crack nucleation agents, the deformed graphite fines were not broken off from the surface in a short time. No remarkable changes were relatively observed in the wear mechanisms. At a normal impact angle, material loss from the nodular cast iron surface occurred via gauging. Deformation spreading was also observed beneath the surface under at all impact tests. As far as gray cast iron is considered, the erodent can cause plastic yielding in the target surface and material removal went on by major ploughing with microcracking and subsurface fatigue. At a normal impact angle, the erosive wear occurred by chipping and small-scale fracture.

Materials Science and Engineering: A, 2010

In this study, two surface processes, TIG surface melting and chilling, were applied to remove th... more In this study, two surface processes, TIG surface melting and chilling, were applied to remove the negative effect of the near-surface graphite phases of nodular cast iron. Afterwards, the treated surfaces were plasma-nitrided and boronized. After graphite elimination processes, plasma nitriding and boronizing, the microstructures were compared with the one of untreated cast iron. The results showed that the chilling process that was applied during the casting process of nodular cast iron did not eliminate the graphite phases from the surface. However, an almost nodule-free surface was obtained by the TIG melting process. It was of no use in nitriding and boronizing the chilled surfaces due to the existence of superficial nodular graphite in the surfaces after completion of the chilling. On the other hand, a continuous uninterrupted compound layer and boride layer were observed on the TIG melted surface. Under the light of these experimental studies, the TIG surface process is proposed to eliminate the nodular graphite on flat and curved surfaces of nodular cast iron parts before thermochemical surface hardening treatments or hard coating processes are applied to the nodular cast iron surfaces.

Journal of Materials Processing Technology, 2003

... References. [1] MB Karamış and R. İpek, An evaluation of possibilities of the carbonitride si... more ... References. [1] MB Karamış and R. İpek, An evaluation of possibilities of the carbonitride simple steels instead of carburized low alloy steels (wear properties). Appl. Surf. Sci., 119 (1997), pp. 25–33. [2] JL Arques and JM Prado, The dry wear resistance of a carbonitrided steel. ...

Journal of Materials Processing Technology, 2003

In this study, ISO Cu-DHP tubes were brazed using different filler metals such as AWS BCuP-2, BCu... more In this study, ISO Cu-DHP tubes were brazed using different filler metals such as AWS BCuP-2, BCuP-3, BCuP-5, BAg-16, and DIN L-CuP7 and L-Ag40Cd. The microstructures of the brazed zone of tubes were examined with optical and scanning electron microscopic studies. Hardness measurement and leak-tight tests were conducted. The discontinuities in the brazed zone were determined. The microstructures of the

Wear, 2005

The wear behaviour of the Al-Mo-Ni coating on piston ring material against gray cast iron was inv... more The wear behaviour of the Al-Mo-Ni coating on piston ring material against gray cast iron was investigated under dry and lubricated conditions at elevated temperatures. AISI 440C steel material, widely used in manufacturing piston ring for two-cycle engines, was coated by plasma spraying method including Al-Mo-Ni powders. Wear tests were carried out on a universal wear tester with a loading of 83, 100, 200 and 300 N, and at elevated temperatures of 25, 100, 200 and 300 • C under dry and lubricated conditions. In conclusion, the material loss of the Al-Mo-Ni composite coating is increased with elevated temperatures under dry and lubricated sliding conditions. The material loss is sharply increased up to temperature point of 100 • C under dry sliding condition while it is nearly constant after this point with test loading of 100 N. Under lubricated conditions, the same tendency can be obtained for loading of 83 N. The wear mechanism is mixed mode such as abrasion, scuffing, delamination for dry conditions. Under lubricated conditions, for the lower temperature, the absorbed oil inclusions in the porosities postpone the wear in progress, resulting in easy friction. The wear mechanism of Al-Mo-Ni coating is predominantly abrasive, and delamination also occurs under heavy loading. The wear of the coating under lubricated conditions is nearly 10 times lower than that of dry conditions.