Materials processing and inspection technology

An auxetic structure or material has a property of negative Poisson’s Ratio, which means it contracts when subjected to compressive load, as opposed to normal materials that expand when compressed. This project involves designing 3D auxetic structures on a CAD system and then 3D printing them in plastics. These structures will be subjected to compressive testing to study their auxetic behaviour and we'll carry out a finite element analysis of one structure. We'll also compare the experimental results and numerical results of Poisson’s ratio and mechanical properties. 

The remanufacturing industry plays a key role in saving resources and improving manufacturing sustainability, particularly for high-value products such as superalloy components that are widely used in aerospace, power generators and nuclear plants. Laser Melting Deposition (LMD) is considered as being suitable for precision repair and restoration of industrial gas turbines and aerospace engine components, due to its better controllability of heat input and smaller heat-affected zones compared with conventional welding. 

Our research investigates the design of materials, process modelling and optimisation, mechanical properties and characterisation, and in-process monitoring and control in order to produce defect-free parts with desired properties. 

In partnership with SPEE3D, this project studies the effect of part-build orientation on the tensile mechanical properties of cold sprayed metal parts. Cold spray additive manufacturing involves metal powders being sprayed at supersonic speed onto a substrate and deposited without melting to create parts, layer by layer.  We will fabricate tensile samples in aluminium or copper with different build orientations on the new Spee3D Cold Spray 3D Printing machine located inour Factory of the Future and carry out tests. The investigation will involve studies of stress–strain behaviour, microhardness, fracture mode and porosity using various characterisation facilities.

This project involves designing and additively manufacturing different lattice core geometries using the selective laser melting (SLM) process. We'll test the structural performance of these structures using three-point bend tests and analyse mechanical properties such as flexural strength and flexural modulus. SLM is a metal additive manufacturing process that involves a laser beam melting and fusing metal powder, layer by layer, to create a part. This technology is considered one of the upcoming techniques to manufacture near-net-shape components for the automobile, aerospace, defence and biomedical industries. In future structural applications there is a strong need for the components to have a reduced weight with significant retention of the mechanical properties.

In partnership with BAE Systems Australia, we’re investigating various topology optimisation  models and their applicability to additive manufacturing parts. The layer-by-layer approach of additive manufacturing enables fabrication of components with complex shapes using volume optimisation techniques like topology optimisation. Manufacturing industries are always evolving their technologies to improve component performance, and one of the most desirable results is to significantly reduce component weight. Topology Optimisation is a design solution that mathematically solves for optimal material distribution within the required design domain under a set of constraints. Applying this solution for structural components would significantly lower the costs of parts. 

Many near-net-shape manufactured parts (from casting, forging or additive manufacturing) require machining, grinding and polishing to achieve net shape with surface integrity. The difficulty escalates for difficult-to-machine materials such as Ni-based superalloys, which cause severe tool wear. Our research aims to develop an integrated robotic solution that can deploy hybrid material removal processes to achieve the final finishing dimension accuracy and surface quality. This includes the material removal modelling, in-process tool condition monitoring, materials characterisation, optimal tool path planer and precise material removal rate control. 

In partnership with BAE Systems Australia and Sutton Tools, we’re studying the cutting tool life of hard-to-machine materials such as titanium. This enables many industry partners to optimise the machining process through the selection of appropriate cutting tools, process optimisation and avoiding chatter during machining. Appropriate cooling methods such as cryogenic coolant, cryogenically cooled air and flood coolant types have also been used. All of these will assist with lengthening cutting tool life and reducing the cost of the manufacturing process.

Additively manufactured components are gaining popularity in aerospace, automotive and medical engineering applications as this approach offers tremendous cost advantages over traditional manufacturing methods. However, inter- and intra-layer defects are observed in the additive manufacturing (AM) of components and the lack of appropriate testing methods for assessing their integrity deters the use of AM. 

As non-destructive testing (NDT) is the most common and convenient way of inspecting parts, our research focuses on using a Laser Ultrasonic technique for the inspection of AM components.  

Conveyor systems are the main means of transport in the mining industry, meaning there is a growing need for conveyor condition monitoring. A conventional conveyor system consists of various mechanical components, so if even a single component malfunctions this may lead to significant downtimes and safety hazards. A regular maintenance plan is required to overcome defects by predicting the failures at a very early stage. There are major barriers to achieve continuous monitoring in real time along the conveyor length, normally distributed over kilometres of area. 

Distributed fibre optic sensing technology is currently used in condition monitoring of infrastructure such as bridges and pipelines. The fibre optic sensors have the capability to detect variations in strain, temperature, vibration and acoustic signals. The detection of vibration and acoustic signals can be used to identify the early damage stage and its progression in the conveyor system. Our smart failure detection system for conveyor systems is being developed for distributed fibre optic sensing technology. 

In partnership with Powercor, we’re developing a non-destructive testing method to monitor the condition of timber power poles. Timber power pole systems are extensively used in power and telecommunication networks around the world. Timber has high initial strength but is susceptible to fungus and termite attacks, resulting in deterioration over time. It is difficult to notice defects from the outside and, in most cases, the defects are also below the ground. Ourresearch is focused on developing a non-destructive testing (NDT) method based on a wave propagation technique that can help monitor the condition of the timber poles in-ground.