Category
Applied
Description
Syntactic foams are high-performance materials consisting of a material matrix embedded with hollow particles. This study investigates the crystallization behavior of a nylon 6 material with hollow glass micro balloons for the purpose of elucidating the microstructure and optimizing the properties of the composite through phase-field simulations. This work expands on existing literature by synthesizing material relationships to account for the variation of the interfacial energy with temperature, where the interfacial energy refers to not only that between the amorphous and crystalline phases of nylon 6 but that between any phase of the nylon and the glass micro balloons. Such generalized analysis is necessary to accurately model the microstructure evolution of composites such as syntactic foams, which are also subject to complex, non-isothermal conditions. To validate the model proposed, nylon-6 syntactic foams are prepared from a nylon 6 powder through open-mold casting by first melting the polymer in an oven then removing it to allow solidification. Further, experimental work is underway to verify the results of the model described herein. It was determined that, while many parameters still retain very simplistic forms (linear or even constant with respect to crystallinity and/or temperature), the interfacial energy formulation given herein is more detailed than most contributions from existing polymer-solidification phase-field models in the literature. Additionally, the derived temperature-dependence of the nylon-6/glass boundary condition showed favorable adhesion properties, indicating that the inclusion of a proper volume fraction of glass micro balloons shows strong potential for increasing the primary nucleation density and hence the mechanical properties of the material. Implementation of the current model through computational (finite-element) methods, as well as experimental validation of such model, is in-progress.
Non-Isothermal Phase-Field Model of PA6 Crystallization
Applied
Syntactic foams are high-performance materials consisting of a material matrix embedded with hollow particles. This study investigates the crystallization behavior of a nylon 6 material with hollow glass micro balloons for the purpose of elucidating the microstructure and optimizing the properties of the composite through phase-field simulations. This work expands on existing literature by synthesizing material relationships to account for the variation of the interfacial energy with temperature, where the interfacial energy refers to not only that between the amorphous and crystalline phases of nylon 6 but that between any phase of the nylon and the glass micro balloons. Such generalized analysis is necessary to accurately model the microstructure evolution of composites such as syntactic foams, which are also subject to complex, non-isothermal conditions. To validate the model proposed, nylon-6 syntactic foams are prepared from a nylon 6 powder through open-mold casting by first melting the polymer in an oven then removing it to allow solidification. Further, experimental work is underway to verify the results of the model described herein. It was determined that, while many parameters still retain very simplistic forms (linear or even constant with respect to crystallinity and/or temperature), the interfacial energy formulation given herein is more detailed than most contributions from existing polymer-solidification phase-field models in the literature. Additionally, the derived temperature-dependence of the nylon-6/glass boundary condition showed favorable adhesion properties, indicating that the inclusion of a proper volume fraction of glass micro balloons shows strong potential for increasing the primary nucleation density and hence the mechanical properties of the material. Implementation of the current model through computational (finite-element) methods, as well as experimental validation of such model, is in-progress.
