ACANZ held its 2019 AGM and a technical meeting on Tuesday 19 March.  Hosted by Callaghan Innovation in Lower Hutt, the AGM was well attended with 22 people present.

The AGM was conducted by Trish Shaw, who is entering her second year as NZ Branch President and is Team Leader Simulation, Analysis and Testing, Advanced Materials at Callaghan Innovation.

Trish summarised ACANZ’s 2018 year, complimenting the Auckland Division on another full programme. The Taranaki Division also had a good year with well attended events. Wellington Division is looking forward to a busier year, starting with this AGM and following technical presentation.

Willie Mandeno, Branch Treasurer summarised the key points of the Branch accounts, which are in a good state and will be available along with the auditor’s certificate on the Charities Commission website. In response to question from the floor, Willie advised that sufficient funds are held for the A.C. Kennett prize, which is awarded for the best non-metallic corrosion paper in the ACA’s annual Corrosion and Prevention Conference, and added that A. C. Kennett was a scientist at the DSIR, the predecessor of  Callaghan Innovation.

Willie is also an editor of the Corrosion and Materials Journal and encouraged the audience to contribute an article on an interesting corrosion or ACA topic. Trish summarised the role of the ACA Foundation in encouraging corrosion education.

The Branch committee and officers remain unchanged in 2019.  In General Business Willie recognised that Bill Koelman, a NZ life member was present at the meeting.

Following the AGM Conrad Lendrum, Group Manager, Advanced Materials introduced the host company and the Advanced Materials group, summarising how it advances research through grants and its own research in fields spanning materials, product development and the “internet of things.”

Corrosion Behaviour of Materials Made by Powder-Based Methods – Fishhooks and Opportunities

In the main presentation, Karl Dahm, Principal Scientist, described some of the issues, including corrosion, of 3D printed metals. Karl started by exploring what 3D printing is capable of, including ‘mass customisation’ – mass production of objects that have variety of difference – as opposed mass production of identical objects. He then gave examples of both simple and intricate shapes that can be easily made with 3D printing, but are expensive  to produce using traditional manufacturing techniques.

Moving on to ‘fishhooks,’ Karl made the point that in traditional construction, the welds and the heat-affected zone around welds are always treated as somewhat more prone to corrosion than the bulk of the object, often requiring special treatment. 3D printing of metals involves fusing of layers by heat – either after the item is made using a polymer ‘scaffold’ or as the layers are laid down. The result is that the items are, in effect, all welded and prone to common weld flaws – residual stress, porosity, rough surface finish and lower strength/brittle. These contribute to a greater or lesser extent to the objects being more prone to corrosion, but can be mostly overcome using strict controls on the printing process and appropriate post-treatment techniques.