Mehmet Yaz - Academia.edu (original) (raw)
Papers by Mehmet Yaz
Materials & Design, 2009
The effect of boron additives and heat treatment on the microstructural morphology of the transit... more The effect of boron additives and heat treatment on the microstructural morphology of the transition zone in a duplex cast iron, which has an outer shell of white cast iron (with a high Cr-content and containing boron additives) and an inner side composed of normal gray cast iron, has been investigated. For this purpose, two experimental materials possessing different compositions of white-gray duplex cast iron were produced. Subsequently, metallographic investigations were carried out to study the effect of heat treatment applied to the experimental materials by using the scanning electron microscopy technique, along with optical microscopy and energy dispersive X-ray spectroscopy. Moreover, the formation of various phases and carbide composites in the samples and their effects on the hardness were also investigated using X-ray diffraction techniques. The results of investigations, and hardness showed that addition of the elements Cr and B to high-alloyed white cast iron affected carbide formation significantly, while simultaneously hardening the microstructure, and consequently the carbide present in the transition area of white-gray cast iron was spread out and became thinner. However, B additives and heat treatment did not cause any damage to the transition region of high Cr-content duplex cast iron.
International Journal of Materials Research, 2008
In this study, the hardfacing behavior of Cr – Ni stainless steel was studied by depositing of St... more In this study, the hardfacing behavior of Cr – Ni stainless steel was studied by depositing of Stellite 1, Stellite 6, and Stellite 12 superalloys on Cr – Ni stainless steel specimens using electric arc welding and tungsten inert gas welding. The cobalt base alloys were hardfaced on stainless steel plates as a single layer. The samples taken from the hardfaced materials were studied by optical microscopy, scanning electron microscopy, X-ray diffraction, and microhardness measurements. The hardness and wear resistance values of the layer obtained after the hardfacing processes are satisfactory and the process seem to be suitable for application.
firat.edu.tr
... Parlatılmış yüzeylerin dağlanması için 5ml HNO 3 +5ml C 2 H 4 O 2 +20ml HCl+5ml H 2 O içeren ... more ... Parlatılmış yüzeylerin dağlanması için 5ml HNO 3 +5ml C 2 H 4 O 2 +20ml HCl+5ml H 2 O içeren çözelti kullanılmıştır (Yaz, 2005). 2.4. ... Kobalt (Co), normal şartlarda hsp kafes sistemine sahiptir. 417 o C'den sonra YMK kristal kafes siste-mine dönüşürler (Brooks, 1990). ...
Materials Testing, 2022
In this article, a gas tungsten arc welding is used as a high energy density beam to form a surfa... more In this article, a gas tungsten arc welding is used as a high energy density beam to form a surface over 0.15% carbon steel with FeB, FeMo, and graphite powders. The microstructure, microhardness, and dry-sliding wear behavior of the composite coating were investigated using optical micrography, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectrometry. Microstructural investigations reveal that FeB-reinforced coating exhibited a homogeneous microstructure that consists of dendrites and eutectic. A lot of types of carbide and borides were formed. MoB4, Fe2MoC, B8C, Mo2BC, MoB, Fe3Mo, Fe3B, B25C, Fe7C3, FeB, Mo2B5, and MoC were seen in coated surfaces. Graphite iron boride coatings obtained by the gas tungsten arc welding process improved the wear resistance of carbon steel.
In this investigation, a gas tungsten arc welding (GTAW) is used as a high energy density beam to... more In this investigation, a gas tungsten arc welding (GTAW) is used as a high energy density beam to form a surface over 0.15% C carbon steel with FeB and Graphite powders. The microstructure, microhardness and dry-sliding wear behavior of the composite coating were investigated using optical micrograph (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and adhesive wear tester. A lot of types of carbide and borides were formed. Fe 2 B, B 4 C, Fe 3 C, FeB, Fe 3 B, Fe 7 C 5 , C and α-Fe phases were seen in coated surfaces. The shape of the graphite present in the FeB–C composite TIG welding coatings is various from sheet-like to spherical. Within the wear test conditions used in the present research, on Fe 2 B coated samples wear was essentially oxidative until the failure of the coating. 1. Introduction Different surface techniques were carried out in order to improve surfacing in situ properties of materials....
Bu calismada; FeB FeTi ,FeW ve grafit tozlari, kullanilarak dusuk karbonlu (%0,15 C) celigin yuze... more Bu calismada; FeB FeTi ,FeW ve grafit tozlari, kullanilarak dusuk karbonlu (%0,15 C) celigin yuzeyi, farkli islem parametrelerinde, Gaz Tungsten Ark Kaynak yontemiyle (TIG) kaplanmistir Elde edilen kaplama yuzeyinin mikroyapisi, optik mikroskop (OM) ve taramali elektron mikroskobunda (SEM) incelenmistir. Mikrosertlik ve kuru-surtunme asinma deneyleri yapilmistir. Yogun enerjili X isini analizi (EDS) ile alasim elementlerinin yuzeyden altlik malzemesine dogru dagilimi arastirilmistir. Kaplama bolgesinin mikroyapisinda karbur ve borurlerin olustugu gozlenmistir. Elde edilen sert yuzey kaplamalarinda olusan karbur ve borurlerin sekilleri ucgenden duz kareye donusmustur.
St52 CELIĞININ WC TAKVIYELI TOZLA TIG KAYNAK YONTEMI ILE KAPLANMASI Ihsan Kirik 1 , Zulkuf Balala... more St52 CELIĞININ WC TAKVIYELI TOZLA TIG KAYNAK YONTEMI ILE KAPLANMASI Ihsan Kirik 1 , Zulkuf Balalan 2, Yunus Andan 3, Mehmet Yaz 4 Bu calismanin amaci; farkli oranlarda Co-Cr esasli WC takviyeli tozlarin TIG kaynak yontemi kullanilarak St52 celiginin yuzeyine ergitilmesi yontemi ile kaplamalari yapilmasidir. Farkli ozellikteki celik alt tabakalari uzerine WC-Co-Cr toz karisimlari belirlenen oranlarda onceden yerlestirildi ve TIG kaynak islemi ile kaplama islemleri yapildi. Farkli ozellikteki kaplama tabakalari celik alt tabakaya yogun ve neredeyse hic gozenek olmadan metalurjik bir baglanma gosterdi. Kaplamalarin mikroyapi ve faz analizi icin, taramali elektron mikroskobu (SEM), EDS ve X-Ray incelemeleri yapildi. X-isin kirinimi incelemesi sonucu, kaplamalarda WC’ lerce zengin duzensiz dagilimli otektik yapilarla birlikte birincil dentritik fazlarinda oldugu ayrica WC-Co-Cr kaplamalari WC ve W2C ile CrC ve Cr3C2 karburleri ile Kobalt, Nikel, Karbonun duzensiz dagilim gosteren fazla...
Materials Testing, 2020
The aim of this study was to coat different types of Stellite (1, 6 and 12) whose carbon rates va... more The aim of this study was to coat different types of Stellite (1, 6 and 12) whose carbon rates vary on Hardox 450 and St 52 steel by means of tungsten inert gas (TIG) welding. For the purpose of microstructure investigations after welding, SEM, EDX, X-Ray and microhardness tests were carried out. It was observed that different types of Stellite coating with different features have an effective influence on microstructure and in the presence of dendritic nets between the grains decreased when the carbon content in Stellite coating decreased and when the substrates varied. In addition, it was determined in microhardness examinations that hardness increased with increasing carbon content and that the highest hardness value of 762 HV in sample S1 was attained. Consequently, positive results have been given for coating Hardox 450 steel and St 52 steel with Stellite via the TIG method.
Tribology International, 2009
Titanium diboride (TiB 2) particulate reinforced Fe-based alloy composite coating was produced wi... more Titanium diboride (TiB 2) particulate reinforced Fe-based alloy composite coating was produced with ferrotitanium (FeTi), ferroboron (FeB), ferrotungsten (FeW), ferrochromium (FeCr), ferrovanadium (FeV) and ferromolybdenum (FeMo) powders by using gas tungsten arc welding (GTAW) process. The effects of GTAW processing on the microstructure of AISI-4340 alloy coating with ferro-alloy powders were investigated experimentally. Abrasive wear tests were performed on the coated surface of samples to examine the influence of vol% and the size of boride on wear rates. Depending on the results, it was seen that the samples coated by FeTi-FeW-FeB ferro-alloy powders mixture have the highest wear resistance.
Materials and Manufacturing Processes, 2011
Practical Metallography, 2009
In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was... more In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was investigated based on tool life and tool wear by turning process without coolant on twelve different specimens in as-cast and heat-treated states. Metal removing process was carried out for four different cutting speeds using HSS cutting tools, while a cutting depth of 1.5 mm and a feed rate of 0.1 mm/min were kept constant. The effects of changes in microstructure with respect to addition elements and heat treatments on the tool wear and the hardness were examined. It was seen that the machinability for all of the specimens was not so good with the tools used. Although the hardness of the materials, which were as-casting, increased slightly with increasing the content of Cr and Ni addition elements, the machinability of these materials was not affected positively or negatively with respect to these elements. As heat treatments increased the hardness of the materials, the optimum tool l...
Practical Metallography, 2009
In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was... more In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was investigated based on tool life and tool wear by turning process without coolant on twelve different specimens in as-cast and heat-treated states. Metal removing process was carried out for four different cutting speeds using HSS cutting tools, while a cutting depth of 1.5 mm and a feed rate of 0.1 mm/min were kept constant. The effects of changes in microstructure with respect to addition elements and heat treatments on the tool wear and the hardness were examined. It was seen that the machinability for all of the specimens was not so good with the tools used. Although the hardness of the materials, which were as-casting, increased slightly with increasing the content of Cr and Ni addition elements, the machinability of these materials was not affected positively or negatively with respect to these elements. As heat treatments increased the hardness of the materials, the optimum tool l...
Materials & Design, 2009
The effect of boron additives and heat treatment on the microstructural morphology of the transit... more The effect of boron additives and heat treatment on the microstructural morphology of the transition zone in a duplex cast iron, which has an outer shell of white cast iron (with a high Cr-content and containing boron additives) and an inner side composed of normal gray cast iron, has been investigated. For this purpose, two experimental materials possessing different compositions of white-gray duplex cast iron were produced. Subsequently, metallographic investigations were carried out to study the effect of heat treatment applied to the experimental materials by using the scanning electron microscopy technique, along with optical microscopy and energy dispersive X-ray spectroscopy. Moreover, the formation of various phases and carbide composites in the samples and their effects on the hardness were also investigated using X-ray diffraction techniques. The results of investigations, and hardness showed that addition of the elements Cr and B to high-alloyed white cast iron affected carbide formation significantly, while simultaneously hardening the microstructure, and consequently the carbide present in the transition area of white-gray cast iron was spread out and became thinner. However, B additives and heat treatment did not cause any damage to the transition region of high Cr-content duplex cast iron.
International Journal of Materials Research, 2008
In this study, the hardfacing behavior of Cr – Ni stainless steel was studied by depositing of St... more In this study, the hardfacing behavior of Cr – Ni stainless steel was studied by depositing of Stellite 1, Stellite 6, and Stellite 12 superalloys on Cr – Ni stainless steel specimens using electric arc welding and tungsten inert gas welding. The cobalt base alloys were hardfaced on stainless steel plates as a single layer. The samples taken from the hardfaced materials were studied by optical microscopy, scanning electron microscopy, X-ray diffraction, and microhardness measurements. The hardness and wear resistance values of the layer obtained after the hardfacing processes are satisfactory and the process seem to be suitable for application.
firat.edu.tr
... Parlatılmış yüzeylerin dağlanması için 5ml HNO 3 +5ml C 2 H 4 O 2 +20ml HCl+5ml H 2 O içeren ... more ... Parlatılmış yüzeylerin dağlanması için 5ml HNO 3 +5ml C 2 H 4 O 2 +20ml HCl+5ml H 2 O içeren çözelti kullanılmıştır (Yaz, 2005). 2.4. ... Kobalt (Co), normal şartlarda hsp kafes sistemine sahiptir. 417 o C'den sonra YMK kristal kafes siste-mine dönüşürler (Brooks, 1990). ...
Materials Testing, 2022
In this article, a gas tungsten arc welding is used as a high energy density beam to form a surfa... more In this article, a gas tungsten arc welding is used as a high energy density beam to form a surface over 0.15% carbon steel with FeB, FeMo, and graphite powders. The microstructure, microhardness, and dry-sliding wear behavior of the composite coating were investigated using optical micrography, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectrometry. Microstructural investigations reveal that FeB-reinforced coating exhibited a homogeneous microstructure that consists of dendrites and eutectic. A lot of types of carbide and borides were formed. MoB4, Fe2MoC, B8C, Mo2BC, MoB, Fe3Mo, Fe3B, B25C, Fe7C3, FeB, Mo2B5, and MoC were seen in coated surfaces. Graphite iron boride coatings obtained by the gas tungsten arc welding process improved the wear resistance of carbon steel.
In this investigation, a gas tungsten arc welding (GTAW) is used as a high energy density beam to... more In this investigation, a gas tungsten arc welding (GTAW) is used as a high energy density beam to form a surface over 0.15% C carbon steel with FeB and Graphite powders. The microstructure, microhardness and dry-sliding wear behavior of the composite coating were investigated using optical micrograph (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and adhesive wear tester. A lot of types of carbide and borides were formed. Fe 2 B, B 4 C, Fe 3 C, FeB, Fe 3 B, Fe 7 C 5 , C and α-Fe phases were seen in coated surfaces. The shape of the graphite present in the FeB–C composite TIG welding coatings is various from sheet-like to spherical. Within the wear test conditions used in the present research, on Fe 2 B coated samples wear was essentially oxidative until the failure of the coating. 1. Introduction Different surface techniques were carried out in order to improve surfacing in situ properties of materials....
Bu calismada; FeB FeTi ,FeW ve grafit tozlari, kullanilarak dusuk karbonlu (%0,15 C) celigin yuze... more Bu calismada; FeB FeTi ,FeW ve grafit tozlari, kullanilarak dusuk karbonlu (%0,15 C) celigin yuzeyi, farkli islem parametrelerinde, Gaz Tungsten Ark Kaynak yontemiyle (TIG) kaplanmistir Elde edilen kaplama yuzeyinin mikroyapisi, optik mikroskop (OM) ve taramali elektron mikroskobunda (SEM) incelenmistir. Mikrosertlik ve kuru-surtunme asinma deneyleri yapilmistir. Yogun enerjili X isini analizi (EDS) ile alasim elementlerinin yuzeyden altlik malzemesine dogru dagilimi arastirilmistir. Kaplama bolgesinin mikroyapisinda karbur ve borurlerin olustugu gozlenmistir. Elde edilen sert yuzey kaplamalarinda olusan karbur ve borurlerin sekilleri ucgenden duz kareye donusmustur.
St52 CELIĞININ WC TAKVIYELI TOZLA TIG KAYNAK YONTEMI ILE KAPLANMASI Ihsan Kirik 1 , Zulkuf Balala... more St52 CELIĞININ WC TAKVIYELI TOZLA TIG KAYNAK YONTEMI ILE KAPLANMASI Ihsan Kirik 1 , Zulkuf Balalan 2, Yunus Andan 3, Mehmet Yaz 4 Bu calismanin amaci; farkli oranlarda Co-Cr esasli WC takviyeli tozlarin TIG kaynak yontemi kullanilarak St52 celiginin yuzeyine ergitilmesi yontemi ile kaplamalari yapilmasidir. Farkli ozellikteki celik alt tabakalari uzerine WC-Co-Cr toz karisimlari belirlenen oranlarda onceden yerlestirildi ve TIG kaynak islemi ile kaplama islemleri yapildi. Farkli ozellikteki kaplama tabakalari celik alt tabakaya yogun ve neredeyse hic gozenek olmadan metalurjik bir baglanma gosterdi. Kaplamalarin mikroyapi ve faz analizi icin, taramali elektron mikroskobu (SEM), EDS ve X-Ray incelemeleri yapildi. X-isin kirinimi incelemesi sonucu, kaplamalarda WC’ lerce zengin duzensiz dagilimli otektik yapilarla birlikte birincil dentritik fazlarinda oldugu ayrica WC-Co-Cr kaplamalari WC ve W2C ile CrC ve Cr3C2 karburleri ile Kobalt, Nikel, Karbonun duzensiz dagilim gosteren fazla...
Materials Testing, 2020
The aim of this study was to coat different types of Stellite (1, 6 and 12) whose carbon rates va... more The aim of this study was to coat different types of Stellite (1, 6 and 12) whose carbon rates vary on Hardox 450 and St 52 steel by means of tungsten inert gas (TIG) welding. For the purpose of microstructure investigations after welding, SEM, EDX, X-Ray and microhardness tests were carried out. It was observed that different types of Stellite coating with different features have an effective influence on microstructure and in the presence of dendritic nets between the grains decreased when the carbon content in Stellite coating decreased and when the substrates varied. In addition, it was determined in microhardness examinations that hardness increased with increasing carbon content and that the highest hardness value of 762 HV in sample S1 was attained. Consequently, positive results have been given for coating Hardox 450 steel and St 52 steel with Stellite via the TIG method.
Tribology International, 2009
Titanium diboride (TiB 2) particulate reinforced Fe-based alloy composite coating was produced wi... more Titanium diboride (TiB 2) particulate reinforced Fe-based alloy composite coating was produced with ferrotitanium (FeTi), ferroboron (FeB), ferrotungsten (FeW), ferrochromium (FeCr), ferrovanadium (FeV) and ferromolybdenum (FeMo) powders by using gas tungsten arc welding (GTAW) process. The effects of GTAW processing on the microstructure of AISI-4340 alloy coating with ferro-alloy powders were investigated experimentally. Abrasive wear tests were performed on the coated surface of samples to examine the influence of vol% and the size of boride on wear rates. Depending on the results, it was seen that the samples coated by FeTi-FeW-FeB ferro-alloy powders mixture have the highest wear resistance.
Materials and Manufacturing Processes, 2011
Practical Metallography, 2009
In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was... more In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was investigated based on tool life and tool wear by turning process without coolant on twelve different specimens in as-cast and heat-treated states. Metal removing process was carried out for four different cutting speeds using HSS cutting tools, while a cutting depth of 1.5 mm and a feed rate of 0.1 mm/min were kept constant. The effects of changes in microstructure with respect to addition elements and heat treatments on the tool wear and the hardness were examined. It was seen that the machinability for all of the specimens was not so good with the tools used. Although the hardness of the materials, which were as-casting, increased slightly with increasing the content of Cr and Ni addition elements, the machinability of these materials was not affected positively or negatively with respect to these elements. As heat treatments increased the hardness of the materials, the optimum tool l...
Practical Metallography, 2009
In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was... more In this work, the machinability of Cr-Ni austenitic stainless steels with Si and Mn additives was investigated based on tool life and tool wear by turning process without coolant on twelve different specimens in as-cast and heat-treated states. Metal removing process was carried out for four different cutting speeds using HSS cutting tools, while a cutting depth of 1.5 mm and a feed rate of 0.1 mm/min were kept constant. The effects of changes in microstructure with respect to addition elements and heat treatments on the tool wear and the hardness were examined. It was seen that the machinability for all of the specimens was not so good with the tools used. Although the hardness of the materials, which were as-casting, increased slightly with increasing the content of Cr and Ni addition elements, the machinability of these materials was not affected positively or negatively with respect to these elements. As heat treatments increased the hardness of the materials, the optimum tool l...