Latest Developments in Industrial Hybrid Machine Tools that Combine Additive and Subtractive Operations

Hybrid machine tools combining additive and subtractive processes have arisen as a solution to increasing manufacture requirements, boosting the potentials of both technologies, while compensating and minimizing their limitations. Nevertheless, the idea of hybrid machines is relatively new and there is a notable lack of knowledge about the implications arisen from their in-practice use. Therefore, the main goal of the present paper is to fill the existing gap, giving an insight into the current advancements and pending tasks of hybrid machines both from an academic and industrial perspective. To that end, the technical-economical potentials and challenges emerging from their use are identified and critically discussed. In addition, the current situation and future perspectives of hybrid machines from the point of view of process planning, monitoring, and inspection are analyzed. On the one hand, it is found that hybrid machines enable a more efficient use of the resources available, as well as the production of previously unattainable complex parts. On the other hand, it is concluded that there are still some technological challenges derived from the interaction of additive and subtractive processes to be overcome (e.g., process planning, decision planning, use of cutting fluids, and need for a post-processing) before a full implantation of hybrid machines is fulfilledSpecial thanks are addressed to the Industry and Competitiveness Spanish Ministry for the support on the DPI2016-79889-R INTEGRADDI project and to the PARADDISE project H2020-IND-CE-2016-17/H2020-FOF-2016 of the European Union's Horizon 2020 research and innovation program

Thermomechanical analysis of additively manufactured bimetallic tools for hot stamping

A comparison between a conventional AISI H13 hot stamping tool and a bimetallic tool consisting of an AISI 1045 core and a laser-deposited AISI H13 coating is performed. In order to analyze the performance of bimetallic tools, the material compatibility and quality of the coating are analyzed. Besides, the mechanical properties are evaluated and compared with those of the conventional tool, obtaining mechanically equivalent results. Nevertheless, the real conductivity of the laser deposited AISI H13 is found to be 16 % lower than the theoretical value. Hence, a thermal model of the hot stamping process is developed, and the performance of various coating thicknesses is evaluated. Results show that, in the present case study, an AISI 1045 tool with a 1 mm AISI H13 coating ensures the mechanical properties and reduces the cycle time by 44.5 % when compared to a conventional AISI H13 tool.e authors gratefully acknowledge the financial support for this study from the European Union, through the H2020-FoF132016 PARADDISE project (contract number 723440) and from the Spanish Ministry of Economy and Competitiveness for the support on the DPI2016-79889-R INTEGRADDI project

Study of the Influence of Shielding Gases on Laser Metal Deposition of Inconel 718 Superalloy

The use of the Laser Metal Deposition (LMD) technology as a manufacturing and repairing technique in industrial sectors like the die and mold and aerospace is increasing within the last decades. Research carried out in the field of LMD process situates argon as the most usual inert gas, followed by nitrogen. Some leading companies have started to use helium and argon as carrier and shielding gas, respectively. There is therefore a pressing need to know how the use of different gases may affect the LMD process due there being a lack of knowledge with regard to gas mixtures. The aim of the present work is to evaluate the influence of a mixture of argon and helium on the LMD process by analyzing single tracks of deposited material. For this purpose, special attention is paid to the melt pool temperature, as well as to the characterization of the deposited clads. The increment of helium concentration in the gases of the LMD processes based on argon will have three effects. The first one is a slight reduction of the height of the clads. Second, an increase of the temperature of the melt pool. Last, smaller wet angles are obtained for higher helium concentrations.This work was supported by the DPI 2016-79889-R INTEGRAddi Project and the POCTEFA 90/15 Transfron3D Project. Special thanks are addressed to Praxair (Praxair, Inc., Barakaldo 48903, Spain) for their technical and supply supports in this work

Combination of Laser Material Deposition and Laser Surface Processes for the Holistic Manufacture of Inconel 718 Components

The present work proposes a novel manufacturing technique based on the combination of Laser Metal Deposition, Laser Beam Machining, and laser polishing processes for the complete manufacturing of complex parts. Therefore, the complete process is based on the application of a laser heat source both for the building of the preform shape of the part by additive manufacturing and for the finishing operations. Their combination enables the manufacture of near-net-shape parts and afterwards removes the excess material via laser machining, which has proved to be capable of eliminating the waviness resulting from the additive process. Besides, surface quality is improved via laser polishing so that the roughness of the final part is reduced. Therefore, conventional machining operations are eliminated, which results in a much cleaner process. To validate the capability of this new approach, the dimensional accuracy and surface quality as well as the microstructure of the resulting parts are evaluated. The process has been validated on an Inconel 718 test part, where a previously additively built-up part has been finished by means of laser machining and laser polishing.Special thanks are addressed to the Industry and Competitiveness Spanish Ministry for the support on the DPI2016-79889-R INTEGRADDI project and PARADDISE project H2020-IND-CE-2016-17/H2020-FOF-2016 of the European Union's Horizon 2020 research and innovation program

CAM development for additive manufacturing in turbo-machinery components

Additive Manufacturing (AM) has become a constantly growing up technology due to the suitability and flexibility in terms of geometry and material diversity. It is applied in high value damaged part repairs from aeronautical, medical and molds and die sectors. This paper proposes an Application Programing interface(API) to be implemented in a commercial software (NX-Siemens) with the main objective of covering a full solution to AM simulation challenges. Experimental tests were carried out in a case of study in order to verify the suitability and reliability of the developed API. The selected material (Hastelloy X) is an additional challenge to be faced; some trials were performed to obtain optimal parameters for this material. [All rights reserved Elsevier]

Intelligent nozzle design for the Laser Metal Deposition process in the Industry 4.0

Laser Metal Deposition (LMD) is an AM (Additive Manufacturing) process that enables to build 3D geometries or enhance the surface properties of the base material by the generation of a coating. With the aim of integrating the AM inside the Industry 4.0 trend and improve the quality of the resulting parts, smart nozzles are required. Therefore, authors have developed an intelligent LMD nozzle by means of the integration of various sensing and control systems in a continuous coaxial LMD nozzle prototype. The nozzle is capable of regulating the laser power based on the temperature measurement of the melt pool. Moreover, it adjusts the powder flux that reaches the processing area according to an algorithm that ensures a constant powder income per surface unit area. Lastly, the nozzle evaluates the geometry of the deposited clad using an optical sensor