Opportunities for MSc and PhD students for the following projects (all projects are available now)
Laser welding is a technique with a long history in research and industrial applications. Micro-welding with lasers is also well-established as an engineering process but limitations are encountered when sub-micron positioning accuracies are required post-welding. This presents a challenge in a variety of industries, among them the biomedical industry for the manufacturing of biomedical devices and implants, as well as the telecom industry for micro-attachment applications. Micro-welding components must account for effects such as laser stability which introduces an asymmetric fluid dynamic behaviour of the melt pool which in turn will lead to an asymmetric solidification of the melt. These effects which would be averaged out when welding on the macro level are becoming more important on the micro level.
This project will analyze the achievable positioning accuracies in a two-pronged approach: The students will carry out a numerical analysis of the heat transfer for different configurations for parts A and B which are to be welded, and analyze the distortions introduced by fluctuations of the laser beam power and during the solidification of the melt pool. A second model to predict the residual stresses generated during welding and to predict the mechanical strength of the weld will be developed. The research is complemented by an experimental study of the achievable positioning accuracies for different welding configurations. Mechanical properties of the welded specimens will be determined
This project can accommodate several MSc and PhD students and is suited for candidates with a mechanical engineering or electrical engineering background.
Laser treatment of Magnesium
Thermal processing of Magnesium is challenging because of its volatile behaviour in a heated state. Therefore, virtually no predictable and repeatable, commercially viable thermal joining processes are available.
For this project, an MSc / PhD student will investigate the energy transfer from the laser beam to the target material during a laser welding process experimentally and analytically. This includes building a test stand to carry out actual laser welding of Magnesium. The project is suited for a candidate with a mechanical engineering background.
Biotribology of laser micro-machined orthopaedic implants
This project sets out to develop an advanced manufacturing process capable of micro-machining light metals, most notably titanium and titanium alloys. The process is a key enabler to improving the bio-tribology of orthopaedic implants and improving the international competitiveness of South African companies in the biomedical industry.
As part of this project, the students will build a tribological test stand, carry out a thermodynamic and a mechanical analysis of laser shock processing of Titanium, and investigate the energy transfer from the laser beam to the target material.
It is important that a postgraduate student be capable of making an experimental observation and explain the entailed physical phenomena through analytical and / or mathematical modeling, and vice versa. Therefore, analytical / numerical models to describe the occurring processes are to be developed in parallel.
This AMTS-funded project will accommodate 3 MSc and PhD students and is suited for candidates with a mechanical engineering or electrical engineering background.
Real-time monitoring of water quality
Monitoring of water quality in closed circuits is a known problem in the power generation industry. Water fouling has serious implications on heat exchanger performance and efficiency. A real-time, online diagnostic tool for operation in remote or inaccessible locations, eliminating the need for water sampling and shipment for further analysis, will provide much improved status monitoring capability of water quality in power generation plants.
A MSc / PhD student will develop a probe consisting of a diagnostic train with a fiber optic cable. The probe will be inserted at one access point and will travel downstream to the region of interest. The project is suited for a candidate with a mechanical engineering or electrical engineering background. This is a funded project.