Ejection Performance of Coated Core Pins Intended for Application on High Pressure Die Casting Tools for Aluminium Alloys Processing
Journal Title: Tribology in Industry - Year 2017, Vol 39, Issue 3
Abstract
In high pressure die casting (HPDC) process of aluminium alloys cast alloy soldering severely damages tool surfaces. It hampers casting ejection, reduces the casting quality and decreases the overall production efficiency. Thin ceramic PVD (physical vapor deposition) coatings applied on tool surfaces successfully reduce these effects. However, their performance is still not recognised for surfaces with various topographies. In this investigation, soldering tendency of Al-Si-Cu alloy toward EN X27CrMoV51 steel, plasma nitrided steel, CrN and TiAlN duplex PVD coatings is evaluated using ejection test. The coatings were prepared to a range of surface roughness and topographies. After the tests sample surfaces were analysed by different microscopy techniques and profilometry. It was found that the ejection performance is independent of the chemical composition of investigated materials. After the ejection, the cast alloy soldering layer was found on surfaces of all tested materials. This built-up layer formed by effects of mechanical soldering, without corrosion reactions. Coated samples displayed a pronounced dependence of ejection force on surface roughness and topography. By decreasing roughness, ejection force increased, which is a consequence of intensified adhesion effects. Presented findings are a novel information important for efficient application of PVD coatings intendent for protection of HPDC tools.
Authors and Affiliations
P. Terek, L. Kovačević, A. Miletić, D. Kukuruzović, B. Škorić
Keywords
Related Articles
- EP ID EP229716
- DOI 10.24874/ti.2017.39.03.08
- Views 113
- Downloads 0
Effects of Velocity-Slip and Viscosity Variation in Squeeze Film Lubrication of Two Circular Plates
A generalized form of Reynolds equation for two symmetrical surfaces is taken by considering velocity-slip at the bearing surfaces. This equation is applied to study the effects of velocity-slip and viscosity variation f...
Finite Element Analysis of Temperature Field in Automotive Dry Friction Clutch
The friction clutch design is strongly dependent upon the frictional heat generated between contact surfaces during the slipping at beginning of engagement. Because of that the frictional heat generated firstly will redu...
Wet Friction-Elements Boundary Friction Mechanism and Friction Coefficient Prediction
The friction mechanism for the boundary friction course of friction elements engagement was explicitly expressed. The boundary friction model was built up by the surface topography. The model contained the effect of boun...
Tribological Aspects of the Process of Winding the Steel Rope Around the Winch Drum
Proper winding of the steel rope around the winch drum is great importance, mostly for: prolonging the service life of the rope, reduction of deformations of the body and the sides of the drum if the winding of the rope...
Tribological and Electrical Properties of Filled Epoxy Reinforced Composites
The main goal of this study is to identify the ways in which it is possible to intervene in order to improve the electromagnetic, thermal, thermo-mechanical and mechanical properties of composite materials. One of the ch...