Microstructure modelling of laser metal powder directed energy deposition of alloy 718
Journal article, 2019

A multi-component and multi-phase-field modelling approach, combined with transformation kinetics modelling, was used to model microstructure evolution during laser metal powder directed energy deposition of Alloy 718 and subsequent heat treatments. Experimental temperature measurements were utilised to predict microstructural evolution during successive addition of layers. Segregation of alloying elements as well as formation of Laves and δ phase was specifically modelled. The predicted elemental concentrations were then used in transformation kinetics to estimate changes in Continuous Cooling Transformation (CCT) and Time Temperature Transformation (TTT) diagrams for Alloy 718. Modelling results showed good agreement with experimentally observed phase evolution within the microstructure. The results indicate that the approach can be a valuable tool, both for improving process understanding and for process development including subsequent heat treatment.

Modelling

DED

Heat treatment

Thermal cycle

Phase-field

Author

Chamara Kumara

University West

Andreas Segerstark

GKN Aerospace Sweden

Fabian Hanning

Chalmers, Industrial and Materials Science, Materials and manufacture

Nikhil Dixit

University West

Shrikant Joshi

University West

Johan Moverare

Linköping University

University West

Per Nylen

University West

Additive Manufacturing

2214-8604 (eISSN)

Vol. 25 357-364

Subject Categories

Manufacturing, Surface and Joining Technology

Other Materials Engineering

Metallurgy and Metallic Materials

Areas of Advance

Materials Science

DOI

10.1016/j.addma.2018.11.024

More information

Latest update

2/22/2019