Uğur Çavdar

In-situ compaction and sintering of Al2O3 – GNP nanoparticles using a high-frequency induction system

Abstract In-situ compaction and sintering of nanopowders are of great interest with respect to industrial production because they save time and energy. As a key study, Al2O3-1 wt.-% GNP composites were mixed in a V-type mixer for 2 hours at 35 cycle/min to obtain homogeneous mixtures. Mixed graphene nanoplatelets and alumina nanoparticles were compacted and sintered in-situ by applying uni-axial pressure in a graphite die, heated and generated by the ultra high-frequency induction system (UHFIHS). The graphite die was heated to 1500, 1550, 1600 and 1650 °C for 5, 10 and 20 minutes under a vacuum. The effect of sintering temperature and time on density, surface roughness, hardness and the microstructure of in-situ sintered nano graphene-alumina compacts were investigated.

Energy Consumption Analysis of Sintering Temperature Optimization of Pure Aluminum Powder Metal Compacts Sintered by Using The UHFIS

In this study, pure aluminum (Al) powder metal (PM) compacts are sintered conventional or induction systems. PM compacts are sintered by furnace at 600 ° C in 60 minutes in the conventional sintering process. In the other process, PM compacts are sintered by induction system at seven different sintering temperatures from 550 ° C to 610 ° C in 4 minutes. 2.8 kW, 900 kHz ultra-high frequency induction system (UHFIS) used for heating application of induction sintering process. Densities and hardness values are investigated for both processes. During these sintering processes, all energy consumption results are measured and calculated, than compared with each other. The effects of the sintering time increase in the induction sintering process on energy cost have been analyzed. Optimum sintering temperature of the induction sintering process is determined. It has been seen that the cheaper energy cost is obtained by the induction system for sintering application.

Comparison of electrical energy consumption for different material processing procedures

Abstract The aim of this study is to investigate the electrical energy consumption for different material processing methods. In these experiments, ferrous powder metals, bulk iron and bulk graphite materials are used. These different materials are heated, sintered and welded by using processes of ultra-high frequency induction heating (UHFIH), ultra-high frequency induction heating sintering (UHFIHS) and ultra-high frequency induction heating welding (UHFIHW), respectively. For all experiments, 2.8 kW, 900 kHz ultra-high frequency induction heating system is used. The experiments are conducted by LabVIEWTM based measurement and control system. Finally, all data are analyzed to show the energy efficiency of each process.