Microstructure Based Structure-Property Relationships for the Design of Thin Films and Composite Coatings by Multiscale Materials Modeling
Research output: Book/Report › Doctoral thesis
|Publisher||Tampere University of Technology|
|Number of pages||80|
|State||Published - 23 Nov 2018|
|Publication type||G5 Doctoral dissertation (article)|
|Name||Tampere University of Technology. Publication|
Applications of ICME began from the need for extreme performance, for example involving material solutions for aerospace applications. Another high end application involves surfaces and coatings for wear resistance and lubrication, engaging material challenges for example in transportation or highly abrasive environments such as mining applications. This is also the domain of the current work, i.e., how to systematically develop better wear resistant surfaces and coatings. The speciﬁc challenge is the development, implementation and validation of ICME workﬂows for microstructure founded design of coatings and thin ﬁlms for improved wear resistance. Within this scope, the current work develops a multiscale framework for modeling the microstructure and surface topography of complex multiphase coating microstructures and thin ﬁlms, employing means to model realistic material microstructural morphologies containing also a composite interface character. The behavior of thin solid coatings under sliding abrasive loading is studied, and the possibilities of utilizing Cohesive Zone Modeling (CZM) directly in the modeling of ﬁlm rupture are established. Next, the focus turns toward the introduction of the microstructural modeling of either thin or composite coating solutions, for which the computational methodologies are developed, implemented and validated. The analyzed cases consider primarily cemented carbide microstructures under abrasive tribological loading conditions. The computational methodology is developed further to increase realism with respect to modeling material interfaces, where Finite Element (FE) based models are interfaced to a Phase Field (PF) based modeling of rapid solidiﬁcation microstructures as a result of material processing. After establishing a realistic enough description of the composite microstructure, the focus turns to introducing a modeling solution capable of addressing surface roughness and topography, in relation to other coating characteristics. This introduces a methodology enabling modeling of both the coating topography, its microstructure, interfaces with the bulk substrate, and the microstructure of the substrate itself. ICME workﬂows are discussed, outlined, and set up for the design of wear resistant surfaces utilizing the PSPP principle as a basis, considering especially the microstructure to product linkage in a bottom-up manner. The various use cases support the notion that ICME already provides added value to the solution of tribological problems and material related challenges by adding knowledge for solving problems otherwise diﬃcult and costly to handle. Furthermore, the greatest impact and improved quality of results are obtained when both experimental and modeling approaches are used concurrently and not viewed as alternatives or competitors.