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The paper at hand introduces a 3D printing (3DP) process for additive manufacturing of inorganically bound sand moulds. The fundamental differences to 3DP with organic binders (which is state of the art) are explained and the quality relevant process parameters of the inorganic process are introduced. Since the inorganic binder system is thermally activated during the printing process the main focus lies on the heating procedure. The properties of printed specimens are measured by the quality features fluid migration and strength for which novel methods of moulding sand testing are used. Results show that the identified process parameters have a significant influence on specimen properties. The interaction of the attributes fluid migration and strength are also shown. By understanding the relationship between process parameters and quality features the properties of printed inorganic sand moulds can be tailored to fit casting specific requirements.

An optical measurement test setup was used to determine the elastic modulus of chemically bonded sand as it is used in foundry applications. The surface of the sand specimen was recorded by a stereo camera system during a 4-pointbending test. The images were used to calculate the material's deformation. Three different computational methods to determine Young's modulus were compared. One method was dependent on the displacement data captured by the test machine, and the other two methods were dependent on the data recorded by the optical system. All methods were used to characterize four different sand core materials with organic and inorganic binders. The optical methods are promising to yield more accurate results, as they measure directly on the specimen's surface.

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