Additive.MILLING: add milling to additive manufacturing

Problem Description

The project additive.MILLING - Add Milling to Additive Manufacturing, is a project in co-promotion with the molds industry, the GLNMOLDS, the CDRsp (Centre for Rapid and Sustainable Product Development) of Instituto Politécnico de Leiria and the research centers CEMUC and CMUC of Universidade de Coimbra. Nowadays, the national industry needs to be internationally competitive and hence it needs to be efficient, economically sustainable and it needs to be able to answer quickly to the needs of its clients. Selective laser melting (SLM), which is based on the principle of material incremental manufacturing, has been recognized as a promising additive manufacturing (AM) technology. 



The principle of additive manufacturing lies in fabricating a part layer by layer through a bottom to top approach. The technology is suited for creating geometrically complex components that can not possibly or feasibly be made by any other means. This technique has a weak point related to the superficial finishing. Therefore, in the market, some hybrid technologies have been appearing which integrate the additive process and the subtractive process. In the case of subtractive manufacturing, as opposed to AM principle, material is removed using several techniques, such as, milling. However, the prices of such hybrid technologies are prohibitive for most of our portuguese industry, in particular the molds industry. It is in this context that the project Additive Milling appears. The goal is to integrate both technologies in a step-by-step process, in order to allow the production of high quality molds, with high complexity and low rugosity, without the need of acquiring an hybrid equipment.

(Starting date: January 1, 2016; Duration 24 months).

Modelling & Computational Challenges

The main goal of the additive.MILLING project is to develop an integrated process with a cost adjusted to the industry for which is intended to, allowing the integration of the additive and subtractive technology. The aim is to produce molds with great details, accuracy and finishing. For that an integrated process with different functions will be build to support the additive and subtractive techniques.

Research at LCM

The CMUC team will work in the following problems: Development of a software which will be a support to the additive and subtractive techniques, maximising its advantages; Modelling and numerical simulation of the selective laser melting process for fast prediction of distortions; Development of a software that allows to create a cooling system in order to optimise the injection cycles and the quality of the produced pieces.

Publications

• M. Nhangumbe, J. Gouveia, E. Sousa, M. Belbut, A. Mateus, Geometric study of surface finishing of selective laser melting moulds, Procedia Manufacturing Vol. 12 (2017) pp. 174-182.
• Manuel Nhangumbe, Eixo medial: uma aplicação à fabricação seletiva a laser, Master thesis, Universidade de Coimbra, 2017.
• Carla Jesus, Método ADI para um modelo de fusão seletiva a laser, Master thesis, Universidade de Coimbra, 2017.
• Dulce Silva, Esqueletos retilíneos de polígonos e poliedros, Master thesis, Universidade de Coimbra, 2017. 

CMUC's Project Team

• Ercília Sousa (Contact information)
• João Gouveia
• Sílvia Barbeiro

Project Reference

Projet PT2020-POCI-SII&DT 3414: additive.MILLING - Add Milling to Additive Manufacturing. Co-financed by FEDER (Fundo Europeu de Desenvolvimento Regional), in the scope of the Program Portugal 2020, through COMPETE 2020 (Programa Operacional Competitividade e Internacionalização)