State-of-the-art laser additive manufacturing for hot-work tool steels

Additive manufacturing (AM) processes are based on the controlled selective deposition of material by which a part is manufactured or remanufactured (repaired), layer by layer. Research in AM is drastically on the increase in the last several years owing to the benefits that AM provides over conventional manufacturing i.e. reduction in material usage, time-to-market reduction, improved functionality, increased ability to customize and near-net shape manufacturing. There has been a number of AM techniques focused on non-metallic materials. In addition, many industries have already embraced the use of AM for metallic parts using laser as an efficient machining tool, including automotive, die & mold, aerospace & defense, industrial products, consumer products and health care. However, the research on metallic materials has been facing a lot of obstacles due to the complexity involved in laser additive manufacturing (LAM) process. This complexity arrives from a multitude variables involved in the process itself i.e. system design as well as process design variables. As a result, there are nowadays limited AM technologies commercially available. This can motivate researchers to focus their work in order to ruggedize LAM processes for commercial large-scale. In this regard, this paper gives the definition and classification of additive manufacturing processes according to ASTM Standard F2792-12a, followed by a description of principles and future perspectives for fabrication of parts via LAM focused on hotwork tool steels, and potential future applications of LAM for industries i.e. die & mold, forging and cutting tools and automotive. The present paper also talks about the barriers to implementation of LAM for hot-work tool steels.