Aluminum alloys are widely used in the industry thanks to its many advantages such as light weight and high strength. The use of this material in the market is increasing day by day with the developing technology. Due to the high energy inputs in the primary production, the use of secondary ingots by recycling from scrap material are more advantageous. However, the liquid metal quality is quite important in the use of secondary aluminum. It is believed that the quality of recycled aluminum is low, for this purpose, many liquid metal cleaning methods and test methods are used in the industry to assess the melt cleanliness level. In this study, it is aimed to examine the liquid metal quality in castings with varying temperature using K mold. A206 alloy was used, and the test parameters were selected as: (i) at 725 °C, 750 °C and 775 °C casting temperatures, (ii) different hydrogen levels. The hydrogen level was adjusted as low, medium and high with degassing, as-cast, and upgassing of the melt, respectively. The liquid metal quality of the cast samples was examined by the K mold technique. When the results were examined, it was determined that metal K values and the number of inclusions were high at the as-cast and up-gas liquid with increasing casting temperatures. It has been understood that the K mold technique is a practical method for the determination of liquid metal quality, if there is no reduced pressure test machine available at the foundry floor.

Polymer extrusion is one of the most widely used polymer processing methods and the sole option for many standard products. The modern extrusion machine has a very sophisticated design; for example, the extrusion screw has different zones and complex geometry. Determining the proper processing settings is always a challenge for engineers. Additionally, complex rheological properties of the polymers in extrusion sometimes yield challenging and unpredictable problems to troubleshoot. For convenience, a small-scale extrusion machine can be used to troubleshoot and analyze the polymers rather than the large manufacturing machines that are hard to work with. This study has produced a small-scale extrusion machine that is easy to manufacture without deviating from the extrusion process's nature. The extruder, whose production details are given, was tested with two different polymers: HDPE and PMMA. The correct temperature and screw rotation speed were determined with the extruder for the proper process parameters. In addition, the temperature-viscosity relationship of the polymers' flow nature was also determined.

Endüstride alüminyum, cevherden (birincil alüminyum) ve hurda malzemelerden (ikincil alüminyum) üretilmektedir. Gerek geri dönüşüm ile ülke ekonomisinegerekse rekabet piyasası ile işletmeciye sağladığı katkı ile ikincil alüminyum kullanımı döküm endüstrisinde oldukça fazla yer almaktadır. Ancak ikincil alüminyumun avantajı yapıda bulunan inklüzyonlar, safsızlıklar, hidrojen gazları, oksit filmleri gibi etkenlerin temizlenmesine bağlıdır. Geri dönüşüm yoluyla alüminyumun kullanımında sıvı metal temizliği oldukça önemlidir ve temizleme işlemi için endüstriyel uygulamalarda çeşitli alternatifler mevcuttur. Uygulanan temizleme işleminin uygunluğunun kontrolü ve verimli olup olmadığının belirlenmesi için çeşitli test teknikleri de kullanılmaktadır. Bu çalışmada alüminyum alaşımlarının dökümünde sıvı metal kalitesinin önemi ve temizleme yönteminin uygunluğu için kullanılan test yöntemleri değerlendirilmiştir. Ayrıca yöntemlerin kullanımı ve birbirlerine göre karşılaştırmaları verilmiştir. Sonuç olarak dökümhane pratiğine bağlı olarak güncel test yöntemleri tartışılmıştır.

Manufacturing high-quality casting parts with complex geometries requires high engineering skill and precision. One essential quality concern is isolated hot spots within the castings, often in thick sections. Each hot spot must be consistently fed or mitigated through directional solidification techniques. The impact of various mold sands and the geometry of chill parts on solidification direction was investigated using specialized casting and general-purpose simulation programs. A parametric optimization method was employed to analyze directional solidification to adjust the geometry of the chill parts. The results indicate that employing diverse mold sands to enhance cooling in the thick sections was a viable strategy for achieving directional solidification in parts where the feeding pathway is obstructed due to changes in cross-section. Furthermore, the study revealed that intricate details in the chill part’s geometry are not critical; however, a minimum volume (or weight) was necessary for adequate directional solidification. Lastly, an easily applicable mathematical model has been developed to determine the required volume of chill parts to ensure successful directional solidification.