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- MakaleYalnız künye2022Scopus SJRQ2Investigation of the effect of the addition of grain refiner and modifier addition on wear properties in sand and permanent mould casting of A357 and A380 aluminium alloys
Çolak, Murat; Arslan, İbrahim
The aim of this study is to improve the tribological behaviour of aluminium alloys by using grain refiner and modifier. The effects of Al5Ti1B grain refiner and Al10Sr modifier additives on friction and wear properties on A380, A357 alloys produced by pouring sand andpermanent mould casting were investigated. Abrasion tests were carried out under dry conditions against St1040 steel disc using a pin-disk system with 20 N load and 1.0 m/s sliding speed. It was determined that grain refiner and modifier additives decrease the friction coefficient and increase the wear resistance. It was determined that the samples produced by permanent mould casting method decreased the friction resistance by 9% and the abrasion resistance increased by 40% compared to the samples produced in sand mould. The lowest wear rate was obtained in A380 alloy with TiB and Sr added with a value of 4.87 × 10–11 m2/N.
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İncele - MakaleAçık Erişim2021Scopus SJRQ3The influence of metallostatic pressure, grain refiner, and modification on the critical solid fraction (CSF) of cast A380 alloy
Çolak, Murat; Dispinar, Derya
In this work, porosity formation with regard to the change in the metallostatic pressure was investigated. Different geometry was generated to simulate the effect of pressure on critical solid fraction. A380 alloy was sand cast. Additionally, the effect of grain refiner and modifiers was also investigated. Samples were subjected to X-ray radiography and density measurement to quantify the pore size and distribution.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2019Scopus SJRQ2Modification of eutectic Al-Si alloys by Sr and CuSn5
Çolak, Murat
Enhanced properties can be achieved in Al-Si alloys by several alloying element additions. Typical modifiers are Na, Sr, and Sb that alters Si into a fibrous structure. Fluidity and mechanical properties increase as well as machinability can be improved. In this work, eutectic Al-Si alloy was modified with Al10Sr, CuSn5, and Al10Sr + CuSn5 master alloys. Microstructural characterization was carried out by optical and scanning electron microscopy. Density and hardness of the samples were measured. Wear tests were carried out. It was found that Sr modified Al12Si revealed better performance than CuSn modified.
AtıfScopus21WoS19OpenAlex21İncele - MakaleYalnız künye2017Optimization of Pectin Extraction from Orange Pulp and Characterization of Compositional and Steady Shear Properties
Yilmaz, Mustafa Tahsin; Muslu, Asli; Karasu, Salih; Bozkurt, Fatih; Dertli, Enes
Pectin, which is one of the most important wastes of fruit juice industry, was extracted from orange pulp at optimum conditions (pH, time and temperature) and modified using pectinase. The effect of modification on the structural properties of pectin was monitored using Fourier transformed infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) analyses. The bands at 1600-1800 cm(-1) which indicate the specific region and quality of pectin were detected using FTIR while galacturonic acid content was determined using HPLC. The results showed that the galacturonic acid content of pectin from orange pulp was determined to be 406.44 mg/g powder pectin while that of the modified pectin from the orange pulp was determined to be 465,34 mg/g powder pectin. In addition, flow properties of the pectin samples were determined using rheological analysis. The viscosity and viscoelastic properties of the modified pectin samples were revealed to be different from those of non-modified pectin samples. The consistency index values of unmodified and modified pectin samples were determined to be 0.0559 Pa.s(n) and 0.0046 Pa.s(n), respectively.
AtıfWoS3İncele - MakaleAçık Erişim2017Scopus SJRQ2Taguchi Approach for Optimization of Parameters that Effect Grain Size of Cast A357 Alloy
Çolak, M.; Dlşplnar, D.
Grain refining and modification are common foundry practice for improving properties of cast Al-Si alloys. In general, these types of treatments provide better fluidity, decreased porosity, higher yield strength and ductility. However, in practice, there are still some discrepancies on the reproducibility of the results from grain refining and effect of the refiner's additions. Several factors include the fading effect of grain refinement and modifiers, inhomogeneous dendritic structure and non-uniform eutectic modification. In this study, standard ALCAN test was used by considering Taguchi's experimental design techniques to evaluate grain refinement and modification efficiency. The effects of five casting parameters on the grain size have been investigated for A357 casting alloy. The results showed that the addition of the grain refiner was the most effective factor on the grain size. It was found that holding time, casting temperature, alloy type and modification with Sr were less effective over grain refinement.
AtıfScopus7WoS6OpenAlex7İncele - MakaleYalnız künye2016Rheological and Molecular Characterization of Modified Pectin from Sugar Beet Meal
Yilmaz, Mustafa Tahsin; Muslu, Asli; Dertli, Enes; Toker, Omer Said
The pectin was produced from sugar beet pulp, one of the significant waste of sugar industry, at optimum conditions (pH, time and temperature). Then, the modification was carried out using pectinase. FT-IR (Fourier transform infrared spectroscopy) and HPLC (high performance liquid chromatography) analysis were performed to characterize the differences between modified and unmodified pectin. FT -IR analysis revealed the specific regions of pectin and 1600-1800 cm-1 bands. Galacturonic acid content was analyzed by HPLC. The obtained results revealed that the modified pectin had higher galacturonic acid content. In addition, flow properties of the modified pectin was also determined. The flow characteristics of modified pectin was observed to change.
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