Research Program D: Surface Engineering
Program Leader: Dr. Nick Birbilis – Monash University
The Surface Engineering program is targeted at enhancing light alloy surfaces for optimising durability, corrosion and oxidation resistance, hardness and wear resistance. This entails novel approaches to surface treatment, bulk alloy design, cladding and coating of the light alloys, with the objective of delivering materials with appropriate combinations of bulk and surface properties.
•	Project D1: Surface properties of Mg alloys
	Pure magnesium ignites in the molten state when exposed to air. The target of this activity is to suppress the oxidation of molten Mg by careful alloying additions to alter the surface behavior of magnesium. This involves bulk alloying to influence the nature of the surface films that evolve on the surface of solidifying Mg.
•	Project D2: Durability of light alloys
	In order to expand applications of light alloys into large volume markets, the development of technology to produce more ‘stainless’ light alloys (namely those based upon Mg and Al) is required. This involves detailed fundamental research into elucidating the mechanisms of localised corrosion in such alloys, and subsequently engineering such alloys to control or minimise the cause of corrosion. A key strategic target involves the capability of producing magnesium wheels of adequate strength, toughness and surface durability to permit their widespread introduction into automotive markets. More general targets involve the development of Mg alloys with sufficient corrosion resistance for long-term atmospheric exposure, and development of Al alloys that are immune to failure modes such as intergranular corrosion, along with decreased rates of pit initiation and stress corrosion cracking.
•	Project D3: Surface coatings and cladding
	The target for this project is to enhance surface protection and materials durability, rendered through the chemical, physical or mechanical coating or cladding of a component to create an effective hybrid ‘material’. The approaches adopted will have potential applicability to all three alloy groups (Al, Mg, Ti). Examples of the novel approaches to fabrication that are anticipated or in progress include: Surface coatings applied by sol-gel processing; surface roll bonding, cold cladding/kinetic metallization (which employs a powder feedstock, projected at sufficiently high velocities onto a metal surface that it achieves effective cold welding); and thermal spray (including cold spray).
•	Project D4: Wear resistant light alloys and Project D5: Gradient structures
	The aim of these projects is to enhance the performance of Mg and Al alloys through new approaches to surface engineering, particularly the surface mechanical attrition treatment or alternate processing/forming routes (i.e. ECAP, Cryo-rolling, etc). These approaches can generate a surface layer (or bulk) with nanoscale grain size and attendant improvements in properties. This may be exploited in terms of both the customisation of surface structure, but also, ultimately the surface chemistry (i.e. by exploiting enhanced grain boundary diffusion of nanocrystalline surfaces).