Pascal Mognol

Rapid prototyping: energy and environment in the spotlight

Purpose – To discuss integration of the rapid prototyping environmental aspects with the primary focus on electrical energy consumption.Design/methodology/approach – Various manufacturing parameters have been tested on three rapid prototyping systems: Thermojet (3DS), FDM 3000 (Stratasys) and EOSINT M250 Xtended (EOS). The objective is to select sets of parameters for reduction of electrical energy consumption. For this, a part is manufactured in several orientations and positions in the chamber of these RP systems. For each test, the electrical power is noted. Finally, certain rules are proposed to minimize this electrical energy consumption during a job.Findings – It is important to minimize the manufacturing time but there is no general rule for optimization of electrical energy consumption. Each RP system must be tested with energy consumption considerations under the spotlight.Research limitations/implications – The work is only based on rapid prototyping processes. The objective is to take into cons...

A new DFM approach to combine machining and additive manufacturing

Design for manufacturing (DFM) approaches aim to integrate manufacturability aspects during the design stage. Most of DFM approaches usually consider only one manufacturing process, but product competitiveness may be improved by designing hybrid modular products, in which products are seen as 3-D puzzles with modules realized individually by the best manufacturing process and further gathered. A new DFM system is created in order to give quantitative information during the product design stage of which modules will benefit in being machined and which ones will advantageously be realized by an additive process (such as Selective Laser Sintering or laser deposition). A methodology for a manufacturability evaluation in case of a subtractive or an additive manufacturing process is developed and implemented in a CAD software. Tests are carried out on industrial products from automotive industry.

A new global approach to design for additive manufacturing

Nowadays, due to rapid prototyping processes improvements, a functional part can be built directly through additive manufacturing. It is now accepted that these new processes can increase productivity while enabling a mass and cost reduction and an increase of the parts functionality. However, in order to achieve this, new design methods have to be developed to take into account the specificities of these processes, with the Design For Additive Manufacturing (DFAM) concept. In this context, a methodology to obtain a suitable design of parts built through additive manufacturing is proposed; both design requirements and manufacturing constraints are taken into account.

Manufacturability analysis to combine additive and subtractive processes

Purpose – The purpose of this paper is to propose a methodology to estimate manufacturing complexity for both machining and layered manufacturing. The goal is to take into account manufacturing constraints at design stage in order to realize tools (dies and molds) by a combination of a subtractive process (high‐speed machining) and an additive process (selective laser sintering).Design/methodology/approach – Manufacturability indexes are defined and calculated from the tool computer‐aided design (CAD) model, according to geometric, material and specification information. The indexes are divided into two categories: global and local. For local indexes, a decomposition of the tool CAD model is used, based on an octree decomposition algorithm and a map of manufacturing complexity is obtained.Findings – The manufacturability indexes values provide a well‐detailed view of which areas of the tool may advantageously be machined or manufactured by an additive process.Originality/value – Nowadays, layered manufact...

A new digital chain for additive manufacturing processes

Additive manufacturing is, nowadays, a higher process than most traditional processes (machining, etc.). But there still remains a domain where this process is not very competitive: that being its digital chain. Indeed, it is too poor in information to allow for the development of advanced additive manufacturing operations and therefore to compete with the traditional processes. This paper proposes to use the STEP-NC concept, which contains high-level information, in order to integrate the additive manufacturing processes in a complete STEP-NC digital chain in accordance with the norm work group committee ISO TC 184/SC 1. This paper proposes to develop this digital chain with a classical CNC controller, which is also present in machining equipment, and to hence benefit from their development possibilities.

Toolpaths for additive manufacturing of functionally graded materials (FGM) parts

Purpose – The purpose of this paper is to propose an evaluation of toolpaths for additive manufacturing of functionally graded materials (FGM) parts to ensure the manufacturing of parts in compliance with the desired material distribution. The selection of an appropriate path strategy is critical when manufacturing FGM parts. Design/methodology/approach – The selection of a path strategy is based on a process modeling and an additive laser melting (ALM) system control. To do that, some path strategies are selected, simulated and compared. Findings – The comparison of some paths strategies was applied on a study case from the biomedical field. Test-parts were manufactured and analyzed. Results show a good correlation between the simulated and the deposited material distributions. The evaluation of toolpaths based on the process modeling and the system control was validated. Originality/value – Nowadays, FGM parts manufactured with ALM processes are not functional. To move from these samples to functional p...

Environmental Impact Assessment Studies in Additive Manufacturing

This chapter focuses on the environmental studies in additive manufacturing. For a cleaner production, environmental impacts that occur during the manufacturing phase should be assessed with accuracy. First, the literature on all the studies led to the characterisation of the environmental impact of additive manufacturing processes. The studies on electric energy consumption of these processes are analysed here, and then some studies taking into account raw material and all the flows through the process are detailed. Secondly, a new methodology in order to evaluate, with accuracy, the environmental impact of a part from its CAD model is presented. In this methodology, the work is not focused only on electrical consumption but also on fluids and material consumption which also contribute to the environmental impact. In addition, the inputs of this methodology correspond to the set part process, which allows taking into account different manufacturing strategies and their influences on the global environmental impact. The methodology developed is based on both analytic models (validated by experiments) and experimental models. And finally, an industrial example shows that for some manufacturing strategies, the environmental impact due to electrical consumption is not the predominant one. In this case study, material consumption has an important impact and has to be taken into consideration for a complete environmental impact assessment.

A Method for the Manufacturing of Functionally Graded Material Parts

Developments in additive manufacturing add possibilities to produce three-dimensional industrial parts. Nowadays, customized parts can be obtained in short period directly from digital data. One of major recent evolutions of additive manufacturing is the ability to produce functionally graded material (FGM) parts. These materials can be characterized by the variation in composition and structure gradually over the volume. The use of these materials is particularly attractive in fields such as aeronautical or biomedical where the multimaterial parts allow to modify locally mechanical, chemical, physical or biochemical properties. To move from the design to the fabrication of FGM parts, the necessary steps include representation of the part and determination of a manufacturing strategy to control the process.