• Add to new collection
    Rights: The University of Waikato
    Published 17 September 2009 Referencing Hub media

    In this video, Professor Deliang Zhang and Dr Brian Gabbitas, from the University of Waikato, explain the main thrust of their current research in powder metallurgy. This involves the use of titanium-based alloy powders to forge combustion engine components like valve rockers. They are investigating processing techniques that will produce components equivalent in strength to conventionally made ones but at less cost.


    The main thrust of our current research is to take the powder and to essentially stick it together. There are various ways in which we can do this. At the moment, we are investigating the method which reduces a number of processing steps because that will keep the cost down. So we are looking at things like taking the powder and directly forging the powder into a shape of an engineering component, rather like this engine rocker. We have redesigned this to cut down the weight, and of course, in automotive applications, an important factor in fuel saving is to cut down the weight of any moving components, and this is the first real component that we are going to try and make using this technique.

    This is called a powder metallurgy process. This is actually an alternative metallurgical process for making metallic products in different shapes, different forms without going through the melting stage. We don't have to go through melting, we don't go through forging. Rather, we use this forging and the powder in combination directly, and then we get the products.

    If that doesn't work, in other words, we may be able to stick the powder together to make a 100% dense component, but it may not have the right level of mechanical properties because it has to perform in service and there are stringent requirements for the material. And if that’s the case, then we have to look again at the way we are processing the material and to try and understand, well, why are the mechanical properties not as good as they might be? What can we do? Do we need to change our processing technique? And there are various ways in which we can do this.