Friction-Induced Recycling Process for User-Specific Semi-Finished Product Production

Thomas Borgert,Werner Homberg

doi:10.3390/met11040663

Abstract

Modern forming processes often allow today the efficient production of complex parts. In order to increase the sustainability of forming processes it would be favorable if the forming of workpieces becomes possible using production waste. At the Chair of Forming and Machining Technology of the Paderborn University (LUF) research is presently conducted with the overall goal to produce workpieces directly from secondary aluminum (e.g., powder and chips). Therefore, friction-based forming processes like friction spinning (or cognate processes) are used due to their high efficiency. As a pre-step, the production of semi-finished parts was the subject of accorded research work at the LUF. Therefore, a friction-based hot extrusion process was used for the full recycling or rework of aluminum chips into profiles. Investigations of the recycled semi-finished products show that they are comparable to conventionally produced semi-finished products in terms of dimensional stability and shape accuracy. An analysis of the mechanical properties of hardness and tensile strength shows that a final product with good and homogeneously distributed properties can be produced. Furthermore, significant correlations to the friction spinning process could be found that are useful for the above-mentioned direct part production from secondary aluminum.

Highlights

In recent years, there has been an increasing demand for more flexible manufacturing systems to produce customizable complex products
The aim of the research work described in this paper is to verify the feasibility of a friction-induced recycling process for aluminum chips
A continuously variable, powerful gear motor with a nominal output torque of 19,000 Nm forms the basis of the test rig established at the Chair of Forming and Machining Technology for the friction-induced recycling process of aluminum chips

Summary

Introduction

There has been an increasing demand for more flexible manufacturing systems to produce customizable complex products. The aim of the research work described in this paper is to verify the feasibility of a friction-induced recycling process for aluminum chips. In future, these semi-finished products are to be further processed using the frictioninduced spinning process, which is energy-efficient, in order to create a fully efficient and sustainable production chain. The wires produced with the optimal process parameters showed up to 80% of the tensile strength of the raw material [6] Another promising concept is that of continuous extrusion, on which the process used in this paper is based. The subject of the research described in this paper is a detailed investigation of a friction-induced, energy-efficient and direct manufacturing process of semi-finished products. The self-induced heating process, the electrical power to be applied, as well as the results of the material testing are explained in detail, demonstrating in detail the feasibility presented in the literature

Machine Design

Materials and Methods

Findings

Conclusions