Mühendislik seramiklerinin SLS/M eklemeli imalat yöntemi ile üretilebilirliğinin incelenmesi

Tez Türü: Doktora

Tezin Yürütüldüğü Kurum: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Türkiye

Tez Danışmanı: Prof. Dr. Gökhan Küçüktürk

Tezin Onay Tarihi: 2024

Tezin Dili: Türkçe

Desteklendiği Program: Diğer

Özet:

Additive manufacturing of technical ceramics, especially the realization of a single-step process, is an important goal for ceramic additive manufacturing. In this thesis study, the target material was chosen as alumina. By applying a new approach in the powder bed melting method with the laser beam, additive manufacturing of alumina was studied with laser pairs at two different wavelengths. Within the scope of this thesis, a numerical model has been developed in which laser beams of two different wavelengths are separately defined as heat sources and the properties of alumina that vary with temperature are included. A process window for parameter determination was developed with the numerical model. The numerical model was verified with experimental studies. Samples were produced with various parameter combinations to determine the process parameters. The fact that a dense sample could not be produced due to the relative density of samples produced only with carbon dioxide laser demonstrated the effectiveness of the double laser beam. Samples were produced by applying laser power, scanning speed, scanning distance, layer thickness, and a zigzag scanning strategy at different angle rotations in each layer. Strategies such as rotation of the zigzag scanning strategy at 0˚, 45˚, 67˚, and 90˚ angles, concentric inside-out and outside-in, were used. Two different scanning strategies were developed, and samples with the highest relative density were obtained using these strategies. It has been measured that the pore structure is open porous, and the closed pore ratio is meagre. It has been observed that denser regions are obtained locally in the sample's internal structure at scanning speeds or strategies with longer laser-powder interaction time. It is important to correlate experimental studies with energy density for different parameter combinations, as successful production can be achieved by selecting the appropriate preheating laser power for the parameters used in the study.