The National Research Institute of Mechanical Engineering plans to organize an Institute-level Doctoral Thesis Evaluation Committee for doctoral candidate Nguyen Thai Son in mid-March 2026. The Institute hereby publishes the following information regarding the candidate's doctoral thesis:

Full name of doctoral candidate: Nguyen Thai Son

Scientific supervisors: Assoc. Prof. Dr. Tran Ngoc Hien and Assoc. Prof. Dr. Nguyen Chi Sang

Major: Mechanical Engineering - Code: 9520103

Training institution: National Research Institute of Mechanical Engineering - Ministry of Industry and Trade

Thesis title: “Research on the influence of certain technological parameters on the quality of 3D-SLM printed parts from TI6AL4V material”

Summary of New Conclusions of the Thesis

1. Scientific Significance

- The study identified the main technological parameters affecting the 3D printing process from Ti6Al4V titanium alloy powder using the selective laser melting (SLM) method.

- Established a heat source model, heat transfer model, and analyzed the temperature distribution during printing as a basis for determining the appropriate set of printing technological parameters.

- Established a mathematical model of the relationship between printing technological parameters affecting the output indicator, which is the quality of 3D printed products, serving as a scientific basis for determining the appropriate set of printing technological parameters.

2. Practical Significance

The research results serve as teaching materials, research references, and a basis for application in enterprises that utilize additive manufacturing technology to improve product quality.

3. New Contributions of the Thesis

The new contributions of the thesis include:

- Research to refine the theory of metal 3D printing technology applied to printing Ti6Al4V titanium alloy powder material.

- Simulation analysis of the thermal process during printing, which is a complex process with a decisive influence on the quality of printed products. From this analysis, it is possible to predict the temperature distribution state during printing to ensure the molten state of the material corresponding to the appropriate set of printing technological parameters.

- Developed prediction models for the quality of printed products including laser power (U), scanning speed (V), layer thickness (t) affecting the quality indicators of 3D printed products: dimensional accuracy (D), surface roughness (R_a), and product porosity. In which, single-objective and multi-objective functions were constructed to describe the relationship between the set of SLM printing technological parameters and the output quality indicators.

Detailed content of the doctoral thesis of candidate Nguyen Thai Son here