Initial Situation:
At the start of the project, toolcraft AG had no insight into feasibility in terms of factors such as cracks and the formation of pores when using laser metal deposition (LMD) to process stainless steel 1.4301 as a base material combined with M2 1.3343. Another challenge was to create a process control method for the material bond between the different materials and to reproduce this for delicate component structures.
Goals:
The aim of the project was to perform a feasibility analysis of material and welding processes for components used in the consumer goods industry. The physical task for both materials was to use an appropriate process control method and selection of parameters to adjust the cooling and solidification conditions to create an equiaxed structure that was as fine-grained as possible, allowing the characteristic material properties to be achieved at the greatest possible relative density. Materialographic analyses were conducted for all the specimens built up during the process development work and the parameter range was gradually narrowed down. The hardness and microstructure of the remaining specimens were then analysed. The surface roughness was measured to calculate suitable parameters for the component contours. Further specimens and initial samples were manufactured with the final combinations of parameters.
Process:
The first stage of the project focused on developing an LMD process for machining the multimaterial components. To ensure that the preliminary tests follow a structured workflow, a design of experiment (DoE) was prepared that took into account factors such as laser parameters (spot, exposure speed, power) and process parameters (distance between the nozzle and the substrate, track pitch and path planning).
This was followed by CAM planning and the manufacture of individual tracks. Follow-up steps such as metallographic analyses and heat treatment that are tailored to the chosen process route were then planned before the initial samples were manufactured. Following a visual inspection and metallographic analysis (pores, cracks, hardness, structure), the components were built up layer by layer, the process parameters or laser parameters were adjusted where necessary and the development process was run iteratively. Finally, the newly designed components were manufactured and quality-tested using the developed process route.
