Wear of Shaped Surfaces of PVD Coated Dies for Clinching

Miroslav Džupon,Emil Spišák,Ľuboš Kaščák,Janka Majerníková,René Kubík

doi:10.3390/met7110515

Abstract

A clinching method that uses a simple toolset consisting of a punch and a die, is utilized for joining lightweight materials. This paper is aimed at investigating the wear of the die cavity of a clinching tool. A clinching tool with a specially shaped cavity was used for joining thin hot-dip galvanized steel sheets. Various types of physical vapour deposition (PVD) coatings such as ZrN, CrN and TiCN were deposited on the shaped surface of the die using Lateral Rotating Arc-Cathodes technology. Hot-dip galvanized steel sheets were used for testing the clinching tool. The material properties of PVD coatings that were deposited on the shaped part of the clinching die were evaluated. Finite Element Analysis was used to localize the area of the shaped part of the die and the part of surface area of the cylindrical die cavity of ϕ 5.0 mm, in which high contact pressure values were predicted. The prediction of the start of the wear cycle was verified experimentally by the clinching of 300 samples of hot-dip galvanized steel sheets. Unlike the CrN and ZrN coatings, the TiCN coating remained intact on the entire surface of the die.

Highlights

Mechanical joining technologies, such as clinching, clinch-riveting and self-piercing riveting have been proved effective for joining lightweight materials with high strength
Globulitic particles were detected on the surface of physical vapour deposition (PVD) coatings after deposition; see Figure 2
Various materials including galvanized steel sheets or non-ferrous sheets are joined by this method and thereby affecting the lifetime of the active parts of the clinching tool, the punch and the die

Summary

Introduction

Mechanical joining technologies, such as clinching, clinch-riveting and self-piercing riveting have been proved effective for joining lightweight materials with high strength. Clinching is commonly utilized in car body production [3], building components [4], even in electrical industries. It is a cold joining process of sheets by local hemming with a punch and die. The material between the punch and die is forced into a radial flow to form the undercut. This method belongs among forming joining technologies. The load-bearing capacity of the clinched joint mainly depends on the geometrical parameters of the joint profile, which is mainly influenced by process parameters and the clinching die [5,6,7,8]

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