Molds and cores architectured by sand 3D printing – MONARCHIES

The project is based on the Design for Additive Manufacturing (DFAM) design methodology. To apply this methodology, it is necessary to define, beforehand, the capability of the 3D sand printer according to its 3 axes, the rules of the 3D sand and foundry industry, the degradation laws of the resins associated with molds and molds. additive manufacturing nuclei and the characterization of the thermal properties of sands. All its data are defined by experimentation and by the realization of experimental devices to determine by an inverse method the sought thermal properties. The multi-material approach, made possible by sand 3D printing, offers greater freedom for the design of castings.

The first results obtained on this project are:
- The realization of a 3D sand printer prototype from a robot allowing to use in particular an inorganic binder and different powders (sand, ceramic, metal, ...) in order to control the cooling of parts and the quality metallurgical of these.
- The development and implementation of an experimental device to measure the evolution of degassing nuclei over time and as a function of temperature.
- The development and realization of an experimental device allowing the characterization of the thermal properties of sands by an inverse method in order to feed the database of foundry numerical simulation software
- The draft of a hybrid mold manufacturing methodology based on complexity criteria and tested on industrial cases.

The research work carried out on this project allows us to consider:
- the realization of a 3D sand multi-material and multi-binder printers
- The enrichment of databases of numerical simulation software taking into account the characterization of the thermal properties of various sands in order to simulate the degradation of nuclei and the generation of gas generated
- the programming and the implementation of the methodology of realization of hybrid molds in CAD software
- an optimized methodology for designing and producing architectural molds

1 patent being filed International communication
: 2 publications with peer review (Welding in the World 2017, Rapid Prototyping Journal 2017)
2 ICWAM conferences 2017
National Communication:
1 Manufacturing 2017
1 Additive Manufacturing Symposium and Metallurgy Professions 2017
Broadcast action:
1 Poster: SF2M 2017
1 Poster Symposium Additive Manufacturing and Metallurgy Crafts 2017
other:
Establishment of a collaboration with the software developer ESI around the Core Gas module

The 3D sand printing has a strong impact on traditional smelter know-how due to the lack of tools and the very numerous diverse achievable forms. The project MONARCHIES aims to design and manufacture molds and architected cores with new features in the mold and the workpiece which can be obtained. A paradigm shift for designing parts and molds must take place in order to capitalize on the full potential of 3D sand printing. The topology optimization associated with new business rules for additive manufacturing opens a wide field of designing new foundry products and new forms of molds and cores. The change of sand, binder and modification of print settings have influence on mechanical and physical properties of the mold as well as on castings. This new mold manufacturing technology allows to predict the integration of new features such as vents, coolers, housing for the sensors, ... Before reaching full integration and overcoming some limits of 3D printing for small series, an intermediate step is necessary in which realization of hybrid molds will be undertaken by using the best features of the different manufacturing processes depending on technical and economic criteria. Due to environmental consideration, the study of different types of inorganic binders for 3D printing will be conducted to define the optimal shapes of molds and cores guaranteeing good mechanical properties and ease of removal. Tests will be conducted to characterize the molds and parts obtained by 3D printing and enrich the database software for foundry simulation especially for the sand thermal properties. All these studies will help to control the production of molds and architected cores which represents a new area of development for the foundry of tomorrow.