Dr Muhannad Obeidi
Postdoctoral Researcher

Muhannad obtained his degree in mechanical engineering from Baghdad University in 1988. He was employed by the Iraqi Atomic Energy Commission to work on the assembly, installation and maintenance of high precision CNC machines. He did his master’s degree and PhD at DCU in 2014 and 2018, respectively. He worked as a research assistant at the Advanced Processing Technology Centre (APT) in DCU from January 2015. The research area was mainly focussed on the laser surface processing and texturing of metal insertion for the interference-fit (press-fit) application, which is widely used in the automotive and aerospace industry. The research was also PhD awarded.

Research Interests (Lay Summary)

Current responsibilities include the investigation and optimization of the input processing parameters and their effect on the resulting properties of the additive manufactured (AM) parts. The main processing parameters in AM processes are the laser power, the scanning speed, the laser spot size and the build layer thickness, in addition to the initial powder particle size. The wide range in adjusting these input parameters, which is offered by 3D printers, leads to a wide variation in the resulting properties of the produced part. Such properties include mechanical, physical and chemical properties like the hardness, elastic modulus, final dimensions, porosity, surface roughness, phase change, grain size and colour.

 

Technical Summary

It is important for manufacturers and AM users to understand the relationship between the laser input processing parameters, their levels and the output properties, which will help in the prediction of the part’s performance and life cycle. In order to achieve this aim, an experimental model must be modified in which a statistical description of this relationship can be established. Several instruments are necessary for characterization and measurement.

One of the main challenges in AM processing is the high heating and cooling rates and the differences/increase in the thermal energy between the later layers compared to the early build layers. Our AconityMini metal printer is fitted with a pre-heating element to mitigate this problem and to provide a better control on the heating/cooling rates. The extracted data will be tabulated and used for the optimisation and automation of the AM process.

Expertise

Additive Manufacturing (3D Printing), Bonding/Joining Characterisation, Advanced Manufacturing, Design for Manufacture (DfM), Laser Processing, Metallurgy, Powder Bed Fusion, Surface Engineering

Publications