Project Code: 0901-03
Objectives
Development of DMLD model to provide further understanding in the relationship between the process parameters, material properties and the resulting deposit quality.
Development of a microstructural modelling capability for welded joints in order to provide reduced weld distortion and improvements to static and cyclic performance.
Development of model for FSW of high-temperature materials, and application of the model for the development of improved tool designs.
Project Outline
Direct Metal Laser Deposition
The project will continue the work that was initiated and developed in TWI project 0701-12, to provide a more complete understanding of the phenomena occurring during DMLD. The decoupled DMLD process modelling will be completed by introducing further multi-physical models, in which the interactions between the melt pool and the powders injections, as well as the melt pool dynamics, will be simulated using CFD and FEA. A further understanding will thereafter be established of the effects of significant process parameters. Based on these models, the DMLD process will be optimised in terms of powder efficiency and laser beam efficiency as well as clad quality. It is anticipated that this work will be linked to and supported by that in proposal 0903-8, Laser Deposition for Repair and Cladding Operations, in order to validate the model.
Metallurgical Effects During Welding
The proposed model will have the potential to identify where residual stress and distortion are of concern, and will be used to recommend actions to mitigate these concerns, whilst still obtaining the required microstructure and properties. The proposed work will produce data and develop skills and numerical tools that will allow prediction of the evolution of microstructure and phase transformation for many processes used by TWIs member industries, such as shaped metal deposition, oxidation in thermal barrier protection systems, corrosion, LSND welding, etc. Validation of the model will be provided by experimental results from the linked proposal 0902-4, Control of Residual Stress Via Use of Martensitic Weld Metal with Low Transformation Temperature. The option of participating in a round robin network on weld modelling including microstructural effects is under investigation. This would allow TWI to use experimental data generated by the network in exchange for an in-kind modelling contribution.
Friction Stir Welding of High Temperature Materials
The proposed study aims to develop a numerical model to estimate the forces on the tool and validate it against experimental trials. A successful model will provide potential users of FSW with confidence that the process is well-understood and that recommended welding conditions will be robust. The ability to predict the performance of different tool designs has potential to accelerate process development. This work will be validated using experimental results as described in the linked proposal 0904-6, New Generation Tool Materials for the Friction Stir Welding of High Temperature Materials.
Relevant Industry Sectors