WEB Towards an Ontology for MicrostructuresWednesday (01.01.2020) 00:30 - 00:45 Part of:
Microstructures have an important role in the development and manufacture of modern products. They evolve during processing and also during operation of components and determine the properties of the materials constituting these components and thus eventually the properties of the components along their life cycle.
The presentation depicts the power of concepts used in the European Materials & Modelling Ontology (EMMO)  to describe geometric and topological arrangements of objects typically characterizing the microstructure of materials. EMMO builds on a limited number of relations between things being used to describe their mutual relations. Relevant to the description of microstructures are relations such as “isA” (taxonomy), “connected”, “hasPart” (mereotopology) or “hasProperty” (semiotics).
EMMO allows describing the world seen from different perspectives. In a reductionistic perspective, the microstructure is categorized according to distinct granularity levels: alloy -> grain -> subgrain -> crystallite -> atom. To unambiguously walk between these levels, EMMO introduced the “hasSpatialDirectPart” relation as a non-transitive mereotopological relation. The reductionistic perspective also defines a state as temporal part with constant cardinality. At the granularity level of grains, the microstructure during recrystallisation can e.g. be described as a time series of states, where the states change when a grain is consumed. From a holistic perspective, the recrystallisation is described as a process having grains as participants, while in a perceptual perspective the grain structure is viewed as a geometrical arrangement. In a physicalistic perspective, the microstructure is viewed as a large number of atoms interacting with each other.
Microstructure models in EMMO are defined as signs that not only stand for a physical object or a process, but also are simplified representations aimed to assist calculations for describing the microstructure or predicting its behaviour.
Eventually physical objects can be assigned physical properties. Physical properties being relevant for the description of microstructures especially are the material properties at the different granularity levels, the crystallographic structure and the chemical composition. EMMO provides concepts to effectively describe these properties. Future work towards a comprehensive microstructure ontology will include further metadata descriptors .