Ahlatci H. | Candan E. | Çimenoglu H.

Article | 2004 | Wear257 ( 05.Jun ) , pp.625 - 632

In this study, the effect of Si addition up to 8% Si on the abrasive wear and mechanical properties of Al-Si/60 vol.% SiC composites produced by pressure infiltration technique has been investigated. Optimum properties in terms of improved strength and abrasion resistance without significant loss in toughness were obtained when the matrix alloy contained 1% Si. At Si contents higher than 1%, dramatic decrease of toughness was accompanied a reduction in strength and abrasion resistance. © 2004 Elsevier B.V. All rights reserved.

Ergen S. | Yılmaz F. | Gul S. | Kolemen U. | Kilicaslan M.F. | Uzun O.

Article | 2018 | Advanced Powder Technology29 ( 3 ) , pp.563 - 572

In this study, the effect of Si amount on the microstructure, crystal structure and some mechanical properties of Al-(20,25,30 wt%)Si–5Fe powder mixtures produced by high energy ball milling method was investigated by determining the sintering temperature. In the X-ray diffraction analysis, no inter-metallic phases were found except for the Al, Si and Fe phases of the powder mixtures. The X-ray diffraction patterns were analyzed by the Rietveld method to determine amounts of the Al, Si and Fe elements in the powder mixtures. From the scanning electron microscopy analysis, it is seen that as the amount of Si increases, there is a mar . . .ked decrease in the grain size of powders. In the micro-indentation tests performed at room temperature, the hardness and elastic modulus values of the pelletized powders were found to increase with the amount of Si. It was also found that the Al-20Si-5Fe powder mixture with the lowest Si content had the highest damping capability. The high temperature micro-indentation tests showed that the resulting Al-(20,25,30 wt%) Si-5 Fe powder mixtures started to consolidation at 200 °C and completed the consolidation at 400 °C. This method can be used as an alternative method in the determination of the sintering temperature of materials. © 201 Daha fazlası Daha az

Uysal B.

Article | 2006 | Journal of Applied Polymer Science100 ( 1 ) , pp.245 - 252

A study was conducted to determine the effects of wood pretreatment on the bonding strength of wood materials. The woods used for the test samples (based on BS EN 204) were oriental beech (Fagus orientalis Lipsky), Scotch pine (Pinus sylvestris L.), oak (Quercus petreae Liebl.), and chestnut (Castanea sativa Mill.). They were impregnated with Tanalith-C, creosote, and Protim 230 WR-paraffin by full-cell methods according to ASTM D 1413-76 standards and the directions of the manufacturers. After impregnation, shear strength tests (based on BS EN 205) were applied on the samples bonded with poly(vinyl acetate) (PVAc), Desmodur-VTKA, a . . .nd Pattex fast. The highest shear strength was obtained in nonimpregnated (control) and PVAc-D1 glued oak (5.328 N/mm 2), and the lowest shear strength was obtained in Protim 230 WR-paraffin and Pattex fast glued chestnut (0.169 N/mm2). Accordingly, the impregnation process negatively affected the adhesive bonding strength. Impregnation chemicals, especially containing oily or similar substances, could not be proposed for wood elements exposed to shear strength. © 2006 Wiley Periodicals, Inc Daha fazlası Daha az

Ulubeyli G.C. | Bilir T. | Artir R.

Article | 2017 | Periodicals of Engineering and Natural Sciences5 ( 2 ) , pp.194 - 201

In the ceramic industry, huge amounts of wastes are generated during manufacturing and transportation processes. In order to decrease the need for landfill areas and increase environmentally harmful effects of such wastes, this industry is under pressure to finding effective ways for recycling its wastes and by-products. In addition, the construction industry requires new sources of aggregates due to running out of conventional virgin aggregates, saving energy, and protecting the environment. Therefore, recently, ceramic wastes are often used as coarse and/or fine aggregate both in mortar and concrete. In the present study, effects . . .of using ceramic wastes as coarse and/or fine aggregate on the engineering properties of mortar and concrete are evaluated. These engineering properties are listed and compared according to their mechanical and durability properties. Reviewing of previous studies related with this subject in literature and discussion all results of the studies are conducted as the methodology of this study. Consequently, it was found out that the use of waste ceramic in the conventional concrete or mortar mix as fine/coarse aggregate is suitable as it can improve mechanical and durability properties of the concrete/mortar Daha fazlası Daha az

Gunduz O. | Yetmez M. | Ekren N. | Kilic O. | Ben-Nissan B. | Oktar F.N.

Conference Object | 2018 | Materials Science Forum923 MSF , pp.89 - 92

Nowadays hydroxyapatite (HA) bioceramics are very important because increasing traffic accidents and ageing of the population. They can be produced from synthetic or natural sources with different production methods. The biggest negative issue of HA is being very brittle and unstable under pressure. Various materials are added for restoring these weaknesses, but there is not so much studies adding nano-ingredients for restoring the mechanical properties of HA. In this study, 5-10% nano-yittria-oxide is added to bovine derived HA (BHA) and to commercial synthetic (CSHA) as a control group. Physical and mechanical properties are exami . . .ned. Results show that adding of nano-ingredients are really helping to mechanical properties of HA. © 2018 Trans Tech Publications, Switzerland Daha fazlası Daha az

Salamci E.

Article | 2003 | Turkish Journal of Engineering and Environmental Sciences27 ( 3 ) , pp.169 - 176

Three 7xxx series aluminium SS70, N707 and 7075 alloys have been produced by the spray deposition process. The alloys were extruded and subsequently heat treated in the T6 and T7 temper conditions. Texture analysis of as-received and solution treated alloys revealed and fibre textures leading to higher mechanical properties in the longitudinal direction. Anisotropic behaviour was observed in these alloys. In addition, the influence of recrystallizing, heat treatment, stretching, and processing techniques (IM, PM and spray casting) as well as techniques of forming (extrusion, rolling and forging) on the anisotropic behaviour of the . . . 7xxx series aluminium alloys was examined Daha fazlası Daha az

Gungor A.

Article | 2006 | Journal of Applied Polymer Science99 ( 5 ) , pp.2438 - 2442

In this study, the effect of Fe powder on the physical and mechanical properties of high density polyethylene (HDPE) was investigated experimentally. HDPE and HDPE containing 5, 10, and 15 vol % Fe metal-polymer composites were prepared with a twin screw extruder and injection molding. After this, fracture surface, the modulus of elasticity, yield and tensile strength, % elongation, Izod impact strength (notched), hardness (Shore D), Vicat softening point, heat deflection temperature (HDT), melt flow index (MFI), and melting temperature (Tm) were determined, for each sample. When the physical and mechanical properties of the composi . . .tes were compared with the results of unfilled HDPE, it was found that the yield and tensile strength, % elongation, and Izod impact strength of HDPE decreased with the vol % of Fe. As compared with the tensile strength and % elongation of unfilled HDPE, tensile strength and % elongation of 15 vol % Fe filled HDPE were lower, about 17.40% and 94.75% respectively. On the other hand, addition of Fe into HDPE increased the modulus of elasticity, hardness, Vicat softening, MFI, and HDT values, such that 15 vol % Fe increased the modulus of elasticity to about 48%. © 2005 Wiley Periodicals, Inc Daha fazlası Daha az

Hazer, Baki

Article | 2014 | Journal of Polymers and the Environment22 ( 2 ) , pp.200 - 208

Novel polymer blends based on completely renewable polymers were reported. Polymer blends based on polylactic acid (PLA) and oxidized and hydroxylated soya bean oil polymers were prepared. Plasticization and mechanical strength effect of the soya bean oil polymers on the PLA were observed. Fracture surface analysis of the polymer blends was carried out by using scanning electron microscopy. The PLA blends showed more amorphous morphologies compared to pure PLA. The blends had better elongation at break in view of the stress-strain measurement. Blend of PLA with the hydroxylated polymeric soya bean oil indicated the slightly antibact . . .erial properties. © 2014 Springer Science+Business Media New York Daha fazlası Daha az

Sozen E. | Aydemir D. | Zor M.

Article | 2017 | Drvna Industrija68 ( 3 ) , pp.195 - 204

The aim of this study was to investigate some of the physical, mechanical, thermal and morphological properties of wood fl our and cellulose fiber filled polypropylene composites. Polypropylene as a polymer matrix and wood fl our and cellulose fibers were used as reinforcing fillers to prepare the composites by using a single screw extruder. Physical properties such as density, mechanical properties such as flexure strength and flexure modulus, tensile strength and tensile modulus, and impact strength, thermal behavior with thermogravimetric analysis (TGA/DTA), and morphological characterization with scanning electron microscopy (SE . . .M) of the composites were determined. The density of the composites was found to increase with the addition of fillers. The mechanical properties of the composites showed that the flexure and tensile strength for the composites with wood fl our was higher than the composites with cellulose fibers, whereas flexure and tensile modulus, and impact strength for the composites with cellulose fibers was found to have higher values as compared to the composites with wood fl our. SEM pictures showed that particles and fibers dispersed to different locations in polypropylene matrix. According to the TGA results, thermal degradation of all the composites was found to be lower compared to neat polymer. © 2017, Journal Drvna Industrija. All rights reserved Daha fazlası Daha az

Akyurt N. | Oktar F.N. | Karacayli U. | Yetmez M. | Pazarlioglu S. | Salman S.

Conference Object | 2011 | Proceedings of the Euro International Powder Metallurgy Congress and Exhibition, Euro PM 20112 , pp.195 - 204

Hydroxyapatite (HA, Ca10(PO4)6(OH)2), the main mineral component of bones and teeth, is among the leading biomaterials being an ideal material for grafting purposes in orthopedic and dental applications. The HA bioceramics can be naturally derived or synthetically produced. The synthetic HAs are reliable, but their production is usually complicate and expensive. To develop natural bioceramics seems to be a more economic way. The aim of this study was to develop a novel natural HA from bovine tooth dentine material. For this purpose, bovine teeth were calcined and the enamel was separated from dentine. Dentine parts were ball milled . . .and pressed to green compacts. Those compacts were sintered at 1000, 1100, 1200 and 1300°C. Compression strength, microhardness, and density measurements along with SEM and X-ray diffraction analyses were conducted. From those results (e.g. microhardness was 346HV for sintering at 1300°C) it was seen that bovine dentine derived HA (BDHA) is an interesting and reliable source of HA for producing biomaterials Daha fazlası Daha az

Yetmez M. | Erkmen Z.E. | Kalkandelen C. | Ficai A. | Oktar F.N.

Article | 2017 | Materials Science and Engineering C77 , pp.470 - 475

In this study, sintering effects on microstructural behavior of bovine derived hydroxyapatite doped with powder mullite are considered in the temperature range between 1000 °C and 1300 °C. Results show that maximum values of both compressive strength and microhardness are achieved in the samples sintered at 1200 °C for all mullite additions of 5, 7.5, 10 and 12.5 wt%. Moreover, above 1000 °C, decomposition of HA and new phase formations such as whitlockite and gehlenite play a major role in both compressive strength and microhardness properties which increase up to 10 wt% mullite reinforcement. © 2017 Elsevier B.V.

Öztürk, Temel | Yılmaz-Savaşkan, Sevil | Hazer, Baki

Article | 2008 | Journal of Macromolecular Science, Part A: Pure and Applied Chemistry45 ( 10 ) , pp.811 - 820

In this study, we present the synthesis of poly-MMA macroperoxy initiators obtained by the ATRP of MMA with bromo methyl benzyl t-butyl peroxy ester (t-BuBP) as an initiator, and CuX (X:Br or Cl)/2,2'-bipyridine (bpy) as a catalyst system at 0, 20, 30 and 40C. The peroxygen groups do not decompose during the ATRP reaction, because low reaction temperatures used for the ATRP reaction are not enough to decompose them. The peroxygen groups of poly-PMMA macroperoxy initiators can lead them to react with a monomer by using appropriate reaction conditions to obtain the block or graft copolymers. For this purpose, poly-MMA macroperoxy init . . .iators were used to synthesize poly(MMA-b-S) block copolymers with S and used for graft copolymerization of polybutadiene (PBd) and natural rubber (RSS-3) to obtain crosslinked poly(MMA-g-PBd) and poly(MMA-g-RSS-3) graft copolymers. Swelling ratio values of the crosslinked graft copolymers in CHCl3 were calculated. The characterizations of the polymers were achieved by FT-IR, 1H-NMR, GPC, DSC, SEM, and the fractional precipitation () techniques. The reaction schemes were also performed using the HYPERCHEM 7.5 program. The mechanical properties of the products were investigated Daha fazlası Daha az