Analysis of Hole Quality and Chips Formation in the Dry Drilling Process of Al7075-T6

Numan Habib,Muhammad Aamir,Danil Yurievich Pimenov,Umair Ali,Khaled Giasin,Aamer Sharif,Aqib Hussain

doi:10.3390/met11060891

Numan Habib, Muhammad Aamir + Show 5 more

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https://doi.org/10.3390/met11060891

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Abstract

Millions of holes are produced in many industries where efficient drilling is considered the key factor in their success. High-quality holes are possible with the proper selection of drilling process parameters, appropriate tools, and machine setup. This paper deals with the effects of drilling parameters such as spindle speed and feed rate on the chips analysis and the hole quality like surface roughness, hole size, circularity, and burr formation. Al7075-T6 alloy, commonly used in the aerospace industry, was used for the drilling process, and the dry drilling experiments were performed using high-speed steel drill bits. Results have shown that surface roughness decreased with the increase in spindle speed and increased with the increase in the feed rate. The hole size increased with the high spindle speed, whereas the impact of spindle speed on circularity error was found insignificant. Furthermore, short and segmented chips were achieved at a high feed rate and low spindle speed. The percentage contribution of each input parameter on the output drilling parameters was evaluated using analysis of variance (ANOVA).

Highlights

Drilling is a manufacturing process that is extensively used in many industries such as in the automotive and aerospace industries, where a considerable number of holes are needed for assembly operation [1,2]
Ra is influenced by various machining conditions such as cutting parameters, tool geometry, vibration induced on the workpiece, etc
According to the ISO-based chip classification chart, various chips are formed during the machining operation, ribbonof chips, spiral chips, In the current study,including the evaluation hole helical qualitychips, in thetubular drillingchips, of Al7075-T6 was corkscrew chips, chips, and needle and elemental chips

Summary

Introduction

Drilling is a manufacturing process that is extensively used in many industries such as in the automotive and aerospace industries, where a considerable number of holes are needed for assembly operation [1,2]. Improper drilling parameters, low hole quality, and rapid tool wear may lead to part rejection, which increases the total manufacturing cost and time [6,7]. Aluminium and its alloys have many applications in different manufacturing industries due to their excellent mechanical properties [8,9]. Al7075-T6 is one of the aluminium alloys used for manufacturing aircraft engines, fuselage, aircraft structure, aircraft skin, and internal supporting parts [10]. Various analytical and experimental approaches were previously applied to improve the drilling process on aluminium alloys.

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