Investigation of ignition temperature, time to ignition and chip morphology after the high-speed dry milling of magnesium alloys
Abstract
Purpose
The purpose of this paper is to determine time-to-ignition of magnesium alloy chips and the ignition-preceding stages as well as to examine chip morphology. The tests were conducted according to the following pattern: directly after a milling operation, after ignition using a special test stand located outside the machine tool and after intensive oxidation which prevented ignition.
Design/methodology/approach
Milling is a machining process widely used in the manufacturing of various parts that are applied, e.g. in the aircraft industry. Milling is used for both roughing and finishing machining. In the dry machining of magnesium alloys, spontaneous ignition can occur; therefore, the analysis of chip temperature in the cutting area is of great significance. Additionally, time-to-ignition and chip morphology are crucial when considering the safety of magnesium alloy machining processes.
Findings
The experimental results demonstrate the effect of parameters of the milling process on time-to-ignition of chips made of magnesium alloys AZ31 and AZ91HP. The experiments also involved examining the morphology of a selection of chips produced at the maximum cutting velocity vc and feed per tooth fz. In addition, we analysed the morphology of both ignition products and chips subjected to high temperature where ignition did not occur.
Practical Implications
Based on the time-to-ignition and chip morphology results, it is possible to indicate both safety levels in machining and the efficient range of parameters in the milling of aircraft parts made of magnesium alloys.
Originality/value
The paper presents a new approach to assessing safety in milling operations. The results of the tests of chip flammability (time-to-ignition) which were run at a special test stand placed outside the machine tool enabled determination of both safety and efficiency range of the milling process.
Keywords
Acknowledgements
Financial support of Structural Funds in the Operational Programme – Innovative Economy financed from the European Regional Development Fund – Project “Modern material technologies in aerospace industry”, Nr POIG.01.01.02-00-015/08-00 is gratefully acknowledged.
Citation
Kuczmaszewski, J., Zagórski, I. and Dziubinska, A. (2016), "Investigation of ignition temperature, time to ignition and chip morphology after the high-speed dry milling of magnesium alloys", Aircraft Engineering and Aerospace Technology, Vol. 88 No. 3, pp. 389-396. https://doi.org/10.1108/AEAT-02-2015-0040
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited