Thesis Type: Doctorate
Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2021
Thesis Language: Turkish
Student: KAMURAN KAMİL YEŞİLKAYA
Principal Supervisor (For Co-Supervisor Theses): Yusuf Usta
Co-Supervisor: Mehmet Fatih Aycan
Abstract:
In this study a lower cost manufacturing of bending resistant mechanical parts produced by metal additive method was aimed. Accordingly, bending strength characteristics of Ti-6Al4V test specimens and also a humerus bone plate were investigated for different values of laser power and hatch spacing which are among the additive manufacturing parameters. The effect of two different heat treatment types on bending strength was also researched. The difference in bending strength resulting from the different heat treatment processes was explained by microstructural examinations of the specimens produced based on a standard manufacturing parameters set. The comparison of additive manufactures was made by the material characterization, roughness and density measurements. A lower cost equivalent of the humerus bone plate which would provide higher bending strength was obtained through a structural optimization study. As a result, instead of the standard parameters of the additive machine, parameter sets which can achieve the same level of bending strength at the end of a shorter manufacturing period were found. The lower cost heat treatment method was determined according to the results of different heat treatment procedures. With the help of the finite element method, testing requirements were reduced and verification and validation studies in the simulation environment were made possible. As a conclusion of the optimization study carried out for the humerus plate, a lighter and more bending resistant plate compared to the reference plate has been demonstrated by design, additive manufacturing, analysis and testing studies. Performance tests verified new design and manufacturing type of the finite element model with better results and showed 21,6% reduction in weight and 23,3% increase in strength.
Key Words : Additive manufacturing, Bending strength, Three point bending, Heat
treatment, Microstructural examination, Finite element analysis,
Structural optimization