In this study, heated silicon oil with added carbon and starch powders was used as dielectric liquid, instead of common hydro-carbon based dielectrics, to obtain better hole surface quality with rotating brass tube electrode in electric discharge machining (EDM). The electro-rheometer tests were conducted to find out the suitable temperature and powder concentration values of the electro-rheological (ER) dielectric under the electric field. Higher workpiece material removal rates (MRR) was obtained in carbon powder added dielectrics than the starch powder added ones for rotating and non-rotating electrodes. The optical microscope observations of the machined hole surfaces indicated that the carbon powder added dielectrics reduced the diameter and depth of the discharge craters, thereby resulting in uniformly distributed and round top peaked surface topography. The starch powder addition to the carbon mixed dielectric further improved the surface quality for both rotating and non-rotating electrodes cases at 30˚C and 75˚C dielectric temperatures.

Aluminum alloys of the 7xxx series (AA7075) are preferred in the aerospace and automotive industries due to their low densities, high strength, good corrosion resistance properties. Additionally, these alloys show the most effective aging properties among aluminum alloys. For this reason, it is very important to determine the most appropriate aging parameters for microstructural development. Literature review reveals that the effect of pre-strain on springback has not been studied yet. In this study, the effects of aging temperature, time, and pre-strain on mechanical properties are investigated for AA7075. Precipitates present in solid solutions of AA7075 and their effects are examined. Results reveal that MgZn 2 precipitation is not observed at aging temperatures of 120 and 160 ºC. After the formation of MgZn 2 precipitates, microstructure becomes softer when aging continues at a higher temperature or longer period of time. It is clearly seen that pre-strain causes Portevin-Le Chatelier (PLC) effect after aging at 120 and 160 ºC for aging times of 30 and 90 minutes.

In electric discharge drilling (EDD), rapid local heating and cooling of the workpiece surface by means of electric discharges results in surface layers (recast, heat affected and base material). In this study, the main workpiece surface texture measures, namely the recast layer thickness (RLT) and average surface roughness (R a) characteristics were investigated for varying machining parameters (discharge current and pulse on time). The conducted experiments revealed the strong dependence of surface characteristics on machining parameters.

Gıda sanayi; gıdaların üretimi, işlenmesi, muhafazası, ambalajlanması ve nakliyesini konu alan sanayi dalıdır. Sağladığı katma değer ve satış hasılatları açısından değerlendirildiğinde Türkiye'de ve dünyada sosyo-ekonomik bakımdan kritik önem arz etmektedir. Son yıllarda gıda işleme makinelerinde AISI304 ve AISI316 paslanmaz çeliklerin kullanımı oldukça artmaktadır. Bu makinelerin bazı bileşenlerinde kullanılan aşırı sert ve karmaşık geometrili parçaların imalatı için EEİ yönteminin uygunluğunun araştırılması bu çalışma kapsamında incelenmiştir. Bu amaçla, farklı işleme parametreleri kullanılarak AISI304 ve AISI316 östenitik paslanmaz çelikleri dalma elektro erozyon tezgahında işlenmiştir. Deneysel çalışma sonucunda elde edilen performans çıktıları ve işlenmiş yüzey görüntüleri karşılaştırılmıştır.

Over the past decade, automotive industry has developed considerably faster than other sectors in direction of consumers' demands. In order to provide worldwide emission standards, focusing on new technologies and enhancing fuel efficiency is emerged as a new trend among automobile manufacturers. Producing more efficient, lighter and eco-friendly cars without compromising performance and comfort has been the main goal of automotive industry in recent years. The high technology requirements of passenger cars with internal combustion engines as well as in hybrid and electric cars have directed the companies in sector to investigate alternative production methods. When compared with conventional manufacturing processes, powder metallurgy (PM) production methods are increasingly preferred by automobile manufacturers as they allow both profitability and part production in some special applications. In this review paper, it is aimed to give information about the development and application of PM methods in automotive sector.