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Öğe Characterization of the effect of Sr and Ti on liquid quality in Al8Si3Cu(Springer International Publishing, 2019) Uludağ, Muhammet; Dispinar, D.; Tiryakioğlu, M.Al8Si3Cu alloy was studied to investigate the effect of casting conditions on melt quality of the molten metal. While Sr and Ti master alloys were used as additional parameters, holding time was performed for effect of held liquid. Experimental study was tried before and after degassing. The reduced pressure test machine was used to produce samples which are five samples for each parameter. Samples were prepared by metallographic methods to be analyzed with via digital image processing. Pores on the surface of the samples were measured in number density and distribution of them was examined statistically. Results showed that while Sr addition and holding time increased casting defects by increasing porosity, degassing decreased the number density of defects, as expected. Therefore, it is a vital result that degassing process must be applied to every casting. In addition, Ti addition was found to have a slight positive effect to reduce porosity, but it was almost negligible when compared to that of degassing process. © The Minerals, Metals & Materials Society 2019.Öğe The Effect of Bifilm and Sr Modification on the Mechanical Properties of AlSi12Fe Alloy(Polska Akad Nauk, Polish Acad Sciences, 2020) Uludağ, Muhammet; Gurtaran, M.; Dispinar, D.The microstructure of Al-Si alloy has coarse silicon and this structure is known dangerous for mechanical properties due to its crack effect. Sr addition is preferred to modify the coarse silica during solidification. Additionally, bifilms (oxide structure) are known as a more dangerous defect which is frequently seen in light alloys. It is aimed at that negative effect of bifilms on the properties of the alloys tried to be removed by the degassing process and to regulate the microstructure of the alloy. In this study, the effect of degassing and Sr modification on the mechanical properties of AlSi12Fe alloy was investigated, extensively. Four different parameters (as-received, as-received + degassing, Sr addition, Sr addition + degassing) were studied under the same conditions environmentally. The microstructural analyses and mechanical tests were done on cast parts. All data obtained from the experimental study were analyzed statistically by using statistical analysis software. It was concluded from the results that Sr addition is very dangerous for AlSi12Fe alloy. It can be suggested that to reach high mechanical properties and low casting defects, the degassing process must be applied to all castings whereas Sr addition should not be preferred.Öğe Effect of quenching mediums on mechanical properties of Al-Cu alloy(Stowarzyszenie Techniczne Odlewnikow Polskich/Polish Foundrymen's Association, 2018) Uludağ, Muhammet; Gurtaran, M.; Dispinar, D.[No abstract available]Öğe The effect of SR modification and Ti grain refinement on the mechanical properties of A356(Stowarzyszenie Techniczne Odlewnikow Polskich/Polish Foundrymen's Association, 2018) Uludağ, Muhammet; Dispinar, D.[No abstract available]Öğe Efficiency of Ti addition in A356 alloy under different holding time(Stowarzyszenie Techniczne Odlewnikow Polskich/Polish Foundrymen's Association, 2018) Uludağ, Muhammet; Gurtaran, M.; Dispinar, D.[No abstract available]Öğe Investigation of casting quality change of A356 by duration in liquid state(Springer International Publishing, 2019) Uludağ, Muhammet; Gurtaran, M.; Dispinar, D.This study aims to investigate how casting quality change in aluminum melt during the holding period in liquid state. 10 kg of ingot was melted in a SiC crucible by using an electrical furnace. A sample was taken every five minutes from 0 to 55 min after the alloy was melted. Reduced pressure test (RPT) samples were collected to be solidified under 80 mbar. All samples were sectioned into two parts vertically, and one of them was prepared for metallographic examination. Surface of the samples was subjected to image analysis by using via image analysis software. Bifilm index and bifilm area were analyzed in detail. As a result, it can be concluded that first 30 min of liquid metal is important, because casting quality tends to get worse after 30 min. © The Minerals, Metals & Materials Society 2019.Öğe Investigation of the efficiency of grain refiners on the hot tearing in Al8Si3Cu alloy(Stowarzyszenie Techniczne Odlewnikow Polskich/Polish Foundrymen's Association, 2018) Uludağ, Muhammet; Çetin, R.; Dispinar, D.[No abstract available]Öğe Observation of Hot Tearing in Sr-B Modified A356 Alloy(Polska Akad Nauk, Polish Acad Sciences, 2017) Uludağ, Muhammet; Cetin, R.; Dispinar, D.In this work, T-shaped mould design was used to generate hot spot and the effect of Sr and B on the hot tearing susceptibility of A356 was investigated. The die temperature was kept at 250 degrees C and the pouring was carried out at 740 degrees C. The amonut of Sr and B additions were 30 and 10 ppm, respectively. One of the most important defects that may exist in cast aluminium is the presence of bifilms. Bifilms can form by the surface turbulence of liquid metal. During such an action, two unbonded surfaces of oxides fold over each other which act as a crack. Therefore, this defect cause many problems in the cast part. In this work, it was found that bifilms have significant effect over the hot tearing of A356 alloy. When the alloy solidifies direetionally, the structure consists of elongated dendritic structure. In the absence of equiaxed dendrites, the growing tips of the dendrites pushed the bifilms to open up and unravel. Thus, leading to enlarged surface of oxide to become more harmful. In this case, it was found that these bifilms initiate hot tearing.
