Tailoring the heat transfer on the injection moulding cavity by plasma sprayed ceramic coatings

19th Chemnitz Seminar on Materials Engineering – 19. Werkstofftechnisches Kolloquium

Bobzin, K.^1 ; Hopmann, Ch^2 ; Öte, M.^1 ; Knoch, M.A.^1 ; Alkhasli, I.^1 ; Dornebusch, H.^2 ; Schmitz, M.^2

Surface Engineering Institute at RWTH Aachen, Kackerstr. 15, Aachen

52072, Germany^1

Institute of Plastics Processing at RWTH Aachen, Seffenter Weg 201, Aachen

52074, Germany^2

关键词: Chemical compositions;    Inhomogeneous materials;    Laser flash methods;    Plasma-sprayed ceramic coatings;    Plasma-sprayed coatings;    Thickness distributions;    Variable thermal resistance;    Variable thickness;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/181/1/012013/pdf
DOI  :  10.1088/1757-899X/181/1/012013

来源: IOP

【 摘 要 】

Inhomogeneous material shrinkage in injection moulding can cause warpage in thermoplastic components. To minimise the deformations of the injection moulding parts, the heat transfer during the cooling phase can be adjusted according to the local cooling demand on the surface of the mould cavity by means of plasma sprayed coatings with locally variable thermal resistance over the surface of the mould. Thermal resistance is a function of thermal conductivity and thickness of the coatings, where thermal conductivity of thermal barrier coatings can be adjusted by altering the chemical composition and the microstructure, which is depending on the thickness. This work evaluates the application of plasma sprayed coatings with variable thickness as thermal barrier coatings in the mould cavity. The thermal resistance of the coating and thereby the heat transfer from the melt into the mould will be influenced locally by varying the coating thickness over the cavity area according to the local cooling demand. Using the laser flash method, the thermal conduction of coatings with different thicknesses will be determined. On the basis of the experimentally determined thermal conduction, the effect of the coatings on the temperature field of the mould cavity will be numerically calculated and the required thickness distribution of the coating for an optimal temperature gradient will be determined.