Scholarships

Project 1: Additive manufacturing of high-entropy alloys for marine and offshore applications

Supervisor: Associate Professor Zhou Kun

High-entropy alloys (HEAs), containing five or more elements in high concentrations (5–35 at.%), have emerged as a novel frontier in the metal materials community. HEAs can exhibit remarkable mechanical properties at high temperatures and exceptional strength, ductility and fracture toughness at cryogenic temperatures, as well as superparamagnetism, superconductivity and exceptional irradiation resistance, through screening proper combinations of their constituent elements and regulating their proportions. Therefore, they are considered alternatives in industries for high-temperature turbine blades, high-temperature moulds and dies, hard coatings on cutting tools, components of fourth-generation nuclear reactors, etc. Compared to conventional manufacturing processes such as casting and powder metallurgy, additive manufacturing holds greater promise for the development of HEA products with desirable properties, due to its great flexibility for the design and fabrication of complex and/or customized parts through a layer-by-layer strategy. In particular, the ultrafast cooling rates in additive manufacturing not only contribute to preventing the formation of undesired intermetallic compounds that are commonly produced in conventionally manufactured HEAs, but also lead to the microstructure refinement and resultant mechanical property improvement of HEA products. 

This project will be focused on the additive manufacturing of HEAs for marine and offshore applications. Specifically, laser directed energy deposition (DED) will be utilized to develop HEA products that can be served in harsh environments of marine and offshore. The elements and their ratios of HEAs will be designed for DED by numerical modeling. The printability of the designed HEAs using DED will be evaluated through experimental characterizations. The correlation between process parameters and microstructure of the printed HEAs will be illustrated by scanning electron microscope (SEM), transmission electron microscope (TEM) , electron backscatter diffraction (EBSD) and atomic probe tomography (APT) measurements. The corrosion resistance and mechanical performance (hardness, tensile, fatigue, impact and fracture toughness properties) of the printed HEAs with different process parameters or alloy compositions will be investigated and compared to ASTM standards. This project will provide valuable knowledge on the additive manufacturing of HEAs used for marine and offshore industries. 

Project 2: Investigation of steel bar reinforcement for 3D concrete printing

Supervisor: Professor Tan Ming Jen

Co-supervisor: Assoc Professor Wong Teck Neng

Compared with traditional construction, 3D printing technology, provides a high-level aesthetic freedom and requires lower labor-force.  However, for wide 3D printing application, there is a long way to go.  Currently, a series of studies on 3D printable concrete has been completed, by which researchers has generally obtained optimal materials composition to maintain their pumpability and buildability. Compared with traditional cast in situ concrete, 3D printed concrete has a lower uniformity and larger shrinkage.   A major challenge facing in this technology is an effective way to introduce reinforcement into continuously deposited cementitious material.   Literature review show that, the number of studies on structural performances of 3D printing components is limited.  This project aims to include reinforcement with 3D printing concrete printing to improve structural properties of printed structures.   

This project will explore several approaches to combine steel reinforcement in 3D printing construction: 

1. 3D printed concrete as formworks for structural components. Steel bars can be positioned vertically interlaced for columns or positioned horizontally after the printing of each layer. The influence of the coupling effect of printed concrete, steel reinforcement, strength and aesthetic requirement will be investigated.
2. Printing of concretes at both sides of a steel grid (mesh) with  novel nozzles design and automation.  The approach has a very high-level automation which combined structures with vertical and horizontal reinforcements. 
3. Flexible reinforcement wire coil to be inserted through novel nozzle design while printing of concrete, the influence of longitudinal tensile strength and ductility will be investigated. 

This project aims to include the experiments and numerical simulation on different 3D printed structural components applying various conceptions under loading conditions.