Dimensional Accuracy and Surface Quality of AZ91D Magnesium Alloy Components after Precision Milling.

Jarosław Korpysa,Ireneusz Zagórski,Józef Kuczmaszewski

doi:10.3390/ma14216446

Jarosław Korpysa, Ireneusz Zagórski + Show 1 more

Open Access

https://doi.org/10.3390/ma14216446

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Abstract

This study investigates a precision milling process conducted with the use of conventional end mills and a standard CNC (Computer Numerical Control) machine tool. Milling tests were performed on samples of AZ91D magnesium alloy using TiB2- and TiAlN-coated three-edge end mills measuring 16 mm in diameter. The following technological parameters were made variable: cutting speed, feed per tooth and axial depth of cut. The effects of precision milling were evaluated by analysing the scatter of dimension values obtained in successive tool passes. In addition to that, deviations from the assumed nominal depth as well as obtained ranges of dimension varation were analysed. The study also examined surface quality obtained in the precision milling process, based on the basic surface roughness parameters: Ra, Rz and RSm. Results have confirmed that the use of conventional cutting tools and a standard CNC machine tool makes it possible to manufacture components characterized by relatively small scatter of dimension values and high accuracy classes. Additionally, the results have shown that the type of tool coating and variations of individual technological parameters exert impact on the dimensional accuracy and surface quality obtained.

Highlights

Magnesium alloys are characterized by a low density of only 1.74 g/cm3, which is one of the reasons for a continuous increase in the use of these construction materials
Studies on the milling processes for magnesium alloys confirm that these materials have very good machinability and that it is possible to obtain high quality surface comparable to that obtained by abrasive machining [4,5]
The tools were coated with TiB2 and TiAlN; such tool coatings are widely used in the machining of magnesium alloys

Summary

Introduction

Magnesium alloys are characterized by a low density of only 1.74 g/cm , which is one of the reasons for a continuous increase in the use of these construction materials. These alloys are predominantly used in the aviation and automotive industries where reduced element weight is of key importance. This mainly results from the need to reduce fuel consumption. Owing to their capacity for damping electromagnetic waves, magnesium alloys are used in the electronics industry. Studies on the milling processes for magnesium alloys confirm that these materials have very good machinability and that it is possible to obtain high quality surface comparable to that obtained by abrasive machining [4,5]

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