SEARCH RESULT

This study reports the effect of different size of particulates on wear behaviour of iron (Fe) matrix composites. Fe / 5 wt. % Al2O3 , Fe / 5 wt. % B4C and Fe 2.5 wt. % Al2O3 -2.5 wt. % B4C composites were produced thorough powder metallurgy. The samples were compacted under load of 500 MPa and followed by sintering at 1050 ºC for 1.5 h. The dry sliding wear behaviour of the samples were investigated by reciprocating wear tests under loads of 10, 20 and 40 N. In order to clarify wear mechanisms, worn surfaces were analysed by Scanning Electron Microscopy. The hybrid Fe 2.5 Al2O3 -2.5 B4C composites has the highest wear resistance. Oxidation and delamination are the main wear mechanisms.

International Iron & Steel Symposium
UDCS

Fatih AYDIN

- In this study, Cr-W steels were produced by casting then heat treatment was applied for specimens. After the normalization process at 1100 0C for 1 hour, samples were heated up 660 0C and 760 0C to evaluate the effect of tempering temperature. One group of steel were waited at 1 hour and the other group were waited at 2 hours in these temperatures. Hardness of specimens was measured according to the Vickers test method. Wear tests were performed for all specimens under the loads of 10N, 20N and 40N in dry sliding conditions. Microstructure analysis was carried out using Light Optical Microscope (LOM), Scanning Electron Microscope (SEM). Results show that, tempering temperature significantly affects the wear behaviors of samples. These effects can be seen especially under higher loads. And also there is a direct proportion between wear and hardness results

International Iron & Steel Symposium
UDCS

Fatih AYDIN Yavuz Sun MUHAMMET EMRE TURAN Mustafa ACARER Hayrettin Ahlatçı Yunus Türen

Magnesium have an enormous potential for automobile and aerospace industries due to its low density, high specific strength and good damping ability [1]. However, the low wear resistance and low mechanical properties of Mg hinder the use of Mg in industrial applications [2]. To improve these low properties of Mg, Mg metal matrix composites are widely produced with different reinforcements such as SiC [3], B4C [4], Al2O3 [5]. TiC is a reinforcement material with high hardness and extreme wear resistance [6]. However, the investigation of the effect of TiC on mechanical and wear properties is quite limited.

International Symposium on Light Alloys and Composite Materials
UHAKS

Fatih AYDIN Yavuz Sun MUHAMMET EMRE TURAN Hayrettin Ahlatçı Yunus Türen Mustafa ACARER

Magnesium alloys have great potential in aerospace, automotive and electronic industries due to high specific strength and low densities [1], [2]. Because high specific strength and lightweight materials are needed to improve energy efficiency [3],[4]. However, magnesium alloys have poor mechanical properties, so this situation limits the usage of magnesium in practical applications. There have been a lot of attempts by researchers to overcome deficiencies of magnesium alloys, especially for decades. Researchers develop mechanical properties of magnesium by incorporating reinforcement materials. Micron size reinforcements are generally preferred but nowadays, nano-size materials especially carbon based are becoming popular subject for researchers. In this study, graphene nanoplatelets (GNPs) which is an allotrope of carbon is used as a reinforcement material for magnesium matrix composite. Aluminum was also used to evaluate its binding effects on Mg-GNPs composite. Pure Mg, Mg-0.25 wt.% GNPs, Mg-3Al-0.25 wt.% GNPs and Mg- 9Al-0.25 wt.% GNPs composites were fabricated using semi powder metallurgy technique. GNPs was exposed to ultrasonication process in ethanol for an hour in order to break Vander Waals bonding between carbon atoms. Mg-Al powder (mixed in Turbula mixer for two hours) was added to GNPs/Ethanol solution. Powders were mixed using magnetic stirrer which is connected to the vacuum distillation system. Process was continued until the ethanol removed from the system. Then obtained powder was dried in vacuum drying oven. Dried powders were compacted in graphite mold under 50 MPa applied load in hot pressing device. Argon was used to prevent oxidation and pressing, and sintering temperatures were chosen as 550 ºC. Experimental densities were calculated by Archimedes technique. Microstructures of produced samples were characterized using X-ray diffraction and Scanning Electron Microscope (SEM). Hardness test was applied according to the Vickers test method. Compression tests were performed for all samples to investigate mechanical effects of aluminum and GNPs on magnesium-based composite. Results show that uniform distribution of carbon atoms is seen for GNPs reinforced composites. Figure 1 shows SEM images of Mg-3Al-GNPs and Mg-9Al-GNPs composites. Microstructures are free of macro porosities. As shown in Table 1, hardness of pure magnesium is significantly improved with the addition of Aluminum and GNPs. It can be concluded that reinforcement materials may restrict the dislocation motion and aluminum can exhibit lubricant effect between matrix and GNPs. Compression tests reveal that 0.2% Compression Yield Strength (CYS) and Ultimate Compression Strength (UCS) are enhanced with the addition of reinforcement. Thus, mechanical properties of pure magnesium were significantly improved even low content of carbonaceous reinforcement.

International Symposium on Light Alloys and Composite Materials
UHAKS

MUHAMMET EMRE TURAN Yavuz Sun Fatih AYDIN Hüseyin Zengin Yunus Türen Hayrettin Ahlatçı

Transportation has been one of the most important activities of the human-being since the first eras of the history to the present. The transportation and transmission activities starting with the invention of the wheel have minimized the concepts of time and distance with the use of planes and fast-speed trains at present. The transportation sector is important for economic growth because it enables to put economic resources into good use, build connections with other countries, regulate the flow of goods and ensure the continuity of this process as well as enabling to establish new settlement areas and develop the existing ones and create employment opportunities due to the relationships with other sectors (insurance, warehouse, clearance, packaging etc.). In the present study, the historical development of highway transportation and the policies implemented in this sector in Turkey are investigated in stages. Besides, the relationship between the highway transportation and other transportation systems in Turkey is handled. As a result, it has been concluded that it is necessary to revise the highway transportation-centred policy that was launched in Turkey around 1950 and is still implemented; take alternative transportation networks to the forefront and ensure an absolute integration among these transportation types.

International Rating Academy Congress : Applied Sciences
IRAC

Fatih AYDIN Muhammed Oral