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 94
- Downloads 0
Self-Lubricating Composite Materials for Dry Friction
In certain applications under dry friction, the composites, containing small amount of solid lubricant, work very effectively. The copper matrix composite alloyed with metals and phosphorous and containing globular inclu...
Development of a Constitutive Friction Law based on the Frictional Interaction of Rough Surfaces
Friction has a considerable impact in metal forming. This is in particular true for sheet-bulk metal-forming (SBMF) in which local highly varying contact loads occur. A constitutive friction law suited to the needs of SB...
Reciprocating Wear Behaviour of 7075Al/SiC and 6061Al/Al2O3 Composites: A study of Effect of Reinforcement, Stroke and Load
The wear behaviour comparison of Al/SiC and Al/Al2O3 composites prepared by stir casting technique is investigated to find out the effects of weight percentage of SiC/Al2O3, load and the number of strokes on a reciprocat...
Dry Sliding Wear Behavior of A356 Alloy/Mg2Sip Functionally Graded in-situ Composites: Effect of Processing Conditions
In present study, the effect of dry sliding wear conditions of A356 alloy/Mg2Sip functionally graded in-situ composites developed by centrifugal casting method has been studied. A pure commercial A356 alloy (Al–7.5Si–0.3...
The Accelerated Aging Effect of Salt Water on Lignocellulosic Fibre Reinforced Composites
In recent years natural fibre reinforced composite materials have received an increasing attention in consideration of their biodegradability and admirable mechanical properties. The present paper reveals the experimenta...