Seminar on 3D Printing of Mixed Powders

07 Jun 2022 03.00 PM - 04.00 PM LT6 (NS2-02-05, Level 2, North Spine, 50 Nanyang Ave, Singapore 639798) Current Students, Public

Dr Christopher Hutchinson

Professor 

Department of Materials Science and Engineering, Monash University

This seminar will be chaired by Prof Upadrasta Ramamurty.

Seminar Abstract

Laser powder bed fusion (LPBF) of metals is a popular mode of additive manufacturing (AM) that has the advantage of producing complex shapes with little or no additional processing. However, an important limitation is that the microstructures obtained are relatively simple solidification structures and there are few means available to enrich this. This limits the microstructural complexity that can be achieved and hence the properties obtainable.

In this work, we present and validate a physically-based model to predict the chemical distribution resulting from LPBF of physically mixed powders of different compositions. We demonstrate that mixing of powders with different compositions can be used to generate a deliberately controlled, mesoscale chemical heterogeneity in LPBF that allows the formation of multiphase microstructures and delivers new microstructural complexity to LPBF. A duplex stainless steel, consisting of equal fractions of ferrite and austenite in the as-built state is used as a demonstration of the approach.
The model describing the chemical distribution in the consolidated build can be extended to describe remelting effects and exploited for the design of spatially varying microstructures. This provides a path towards generating architecture materials from random mixes of initial powders.
This opens up an interesting path for delivering microstructural complexity to LPBF of metals.
Speaker’s Biography​

Professor Hutchinson is an expert in the processing, design and properties of engineering alloys, with a particular speciality in Steels, Stainless Steels, Aluminium Alloys, and Coppers & Brasses. His research includes approximately half computational design and modelling (particularly computational thermodynamics and kinetics), and half experimentation. Professor Hutchinson’s research covers aspects of both the mechanical and electrochemical response of alloys, and he works extensively with both Australian and international industry. His work includes alloys produced by conventional processing by wrought and cast means, as well as a large activity in the areas of additive manufacturing. Since 2017, he is an Editor for Acta Materialia and Scripta Materialia. He is currently the co-Chair of the Woodside Energy FutureLab@Monash which is a $20m AUD collaboration between Monash University and Woodside Energy. A major objective of this research centre is the development and qualification of new additively manufactured alloys for use by Woodside Energy as ‘on-demand’ replacements parts. In this role, he has led a program from the stage of conception, through development, qualification and insertion of additively manufactured components in industry that are currently being used.

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