Investigation of the effect of different sintering methods on mechanical properties of composite materials obtained from cast iron waste

Sintering is a technique that is widely used in ceramic, porcelain, and high-tech ceramic works in today's technology. In the last 15 years, the conventional sintering (CS) process has been replaced by different technologies. The most important of these technologies used in this study is flash sintering (FS). Materials sintered by FS are carried out considering temperature, time, energy, cost, environmental pollution, and human health. It is known that the number of foundries in the second quarter of 2023 in the Konya region is 300, but it is increasing day by day. Waste from foundries varies according to the content of the materials produced. It produces products that appeal to the iron-steel and aluminum sectors of the Konya industry. A large amount of metal oxide-containing metal wastes left over from these productions are collected in bulk in foundries, but the scope of the evaluation is very limited. For this reason, in this thesis study, the potential of an environmental benefit and product development has been investigated by evaluating the casting wastes that will harm the environment. In the study, cast iron slag waste (DDCA) is used in powder form and sintered in dog bone-shaped molds by FS, a new sintering method. The results of the CS process with this method were evaluated in terms of physical, chemical, and mechanical strength. The materials produced by the FS method is produced at lower temperatures and in a short time, thus saving energy. In this method, it is observed that the interatomic spaces narrowed due to the electric field and temperature applied to the sample. FS experiments were carried out under an electric field of 20, 25, and 30 V/mm. Physical, chemical, and mechanical tests (3-point bending and hardness) of the sintered materials are carried out. The experimental results obtained from these data, on the other hand, have proven that DDCA sintered at 1000 ºC can be achieved by flash sintering in 20V/mm electric field at 517 ºC within 15 s and it also shows the best mechanical strengths. Although FS processes under 30 V/mm electric field take place at lower temperatures (474 ºC), it has been shown to have lower mechanical properties. For this reason, it has been proven that the mechanical strength of this product obtained from DDCAs, according to ISO 10545 standards, where it can be used in floor and wall tiles, has better strengths than all other sintering processes with FS under 20 V/mm electric field