Investigations on dry sliding of laser cladded aluminum bronze

Hannes Freiße,Thomas Seefeld,Anika Langebeck,Frank Vollertsen,Henry Köhler

doi:10.1051/mfreview/2016012

Abstract

The aim of this study was to investigate the tribological behaviour of laser cladded aluminum bronze tool surfaces for dry metal forming. In a first part of this work a process window for cladding aluminum bronze on steel substrate was investigated to ensure a low dilution. Therefore, the cladding speed, the powder feed rate, the laser power and the distance between the process head and the substrate were varied. The target of the second part was to investigate the influence of different process parameters on the tribological behaviour of the cladded tracks. The laser claddings were carried out on both aluminum bronze and cold work tool steel as substrate materials. Two different particle sizes of the cladding powder material were used. The cladding speed was varied and a post-processing laser remelting treatment was applied. It is shown that the tribological behaviour of the surface in a dry oscillating ball-on-plate test is highly dependent on the substrate material. In the third part a deep drawing tool was additively manufactured by direct laser deposition. Furthermore, the tool was applied to form circular cups with and without lubrication.

Highlights

The vision of avoiding lubricants in metal forming contributes an approach to establish green technology in mass production
It is shown that the tribological behaviour of the surface in a dry oscillating ball-on-plate test is highly dependent on the substrate material
To receive a low dilution, it was evaluated that a lower dilution could be realized by increasing the powder feed rate or applying a lower cladding speed

Summary

Introduction

The vision of avoiding lubricants in metal forming contributes an approach to establish green technology in mass production. This idea of sustainable production in metal forming is summarized by the concept of dry metal forming. The direct contact between the sheet and the tool during dry processing in metal forming causes high load and wear [2]. Aluminum bronze as a tool material provides advantages for forming tools, in particular for cold forming of high alloy austenitic steel due to its excellent friction property and high load capacity [3]. Experiments on ultrafine-grained bulk material showed that grain refinement can improve the wear behaviour and reduce the friction coefficient in dry sliding against 100Cr6 steel. The adhesive wear tendency depended on the mechanical properties caused by applying an equal channel angular extrusion process [4]

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