Test the SLM process at 400W or greater, with a view to substantially increasing the productivity of the process.
Generate procedures around a skin and core approach.
Evaluate the difference between the surface finish achievable using 200W and higher laser powers.
Determine the highest deposition rate achievable using higher laser powers.
Produce a demonstration component to show the benefits of higher productivity SLM.
Initially, the equipment will have to be acquired and installed to carry out the project. The fundamental requirement is for the laser source itself. It will assist greatly in the transferability of the procedures and the operation of the machine in general if the laser sourced has the same beam characteristics as that already installed at TWI. This laser will be borrowed from an equipment supplier and integrated into the existing MTT250 machine at TWI. The optical train installed in this system is already rated at 400W. Should a larger laser be sourced, an optical train will also have to be acquired. The equipment suppliers MTT will assist if there are any software issues, but these are likely to be minor modifications to the core programmes.
The next phase will involve the process development and will create the procedures for the skin and core approach. This will take place as follows:
Validation of existing procedures generated using the 200W source, using the higher power laser at 200W. This will prove the transferability of parameters and that the new laser can be operated effectively at the lower power. Higher power work will be carried out, but often results in a degradation of surface finish. This is the work that will ensure the skin of the part is as suitable as possible.
Several designed sets of experiments (DoE) will be carried out to investigate the processing window involved at high powers. This will involve optimising for processing speed whilst maintaining material quality, ie the minimisation of porosity and solidification defects. This will provide the procedures for the core of the part.
The final phase would involve the application of the above procedures to the creation of industrially relevant components. A least one component would be selected and would be made economically viable due to the step change improvement in processing time achievable because of the results of the project.
Relevant Industry Sectors
The results of this project are directly related to the aerospace, medical and niche areas in the oil and gas, and automotive industry sectors.
Technical and Economic Benefits
The higher productivity SLM developed within this project will allow a wider range of member companies to access ALM for their products.
Additive layered manufacture is a near 100% material utilisation technique that allows complex parts, with re-entrant features, to be created without tooling allowing a true design for function, CAD to part approach. Parts can be designed for performance, repair, recycling, and material usage minimisation, rather than just for manufacture.