Evaluation of the additive manufacturing process in the microstructural and mechanical performance of repairs for injection molds

Abstract

Molds and dies are essential tools in the development and manufacturing of a diversity of parts and components. However, the need for mold and die repair is a consequence of probable design and/or manufacturing errors, material defects, plastic deformation and wear. In turn, conventional arc welding repair processes prove to be insufficient with regard to design, dimensional requirements, time, and process cost. These factors instigated the study and development of new repair techniques, with the laser additive manufacturing process being highlighted as an extremely promising technique. Based on current Additive Manufacturing (AM) technologies, up to 50% time and cost savings can be achieved in tool repair/fabrication, as well as its effectiveness in reproducing complex geometries. Based on this innovative design, the objective of this research is to develop preventive maintenance or repair of molds and matrices, using the additive manufacture by Laser Metal Deposition (LMD), in order to considerably extend the lifetime of these tools. Repairs will be made by additive manufacturing in the received matrix, in order to evaluate the effect of the process parameters of the additive manufacture on the microstructure. The repairs produced by additive manufacture will be characterized for their microstructures, hardness, residual stresses and tensile strength. The mechanical properties in hot tensile stress will be compared with those obtained by the conventional process. (AU)