An experimental study on abrasive waterjet cutting of CFRP/Ti6Al4V stacks for drilling operations

A Alberdi,T Artaza,A Suárez,F Girot,A Rivero

doi:10.1007/s00170-015-8192-x

Abstract

In the present study, CFRP/Ti6Al4V stacks were machined with abrasive water jet using different process parameters in order evaluate the viability of AWJ industrial application as a substitute of conventional drilling. The effect of the stack configuration, the traverse feed rate, the cutting tool (combination of orifice and focusing tube diameter and abrasive mass flow rate), and the pressure over the kerf profile, taper angle, and surface roughness has been analyzed through an ANOVA analysis and related to the physical parameters of the AWJ process. As a result, a positive taper angle is observed in Ti6Al4V while a negative is observed in CFRP in almost all cutting conditions. This leads to obtain an X-type or barrel-type kerf profile depending on the stack configuration. In addition, the surface roughness can be as low as 6.5 μm in both CFRP and Ti6Al4V materials at 95 mm/min when CFRP/Ti6Al4V configuration is used.

Highlights

IntroductionThe difference between the mechanical properties of Ti6Al4V and carbon fiber reinforced plastics (CFRP) is desired for enhancing the strength and the lifetime of the aircraft components, it supposes a big challenge for achieving the high quality of the hole demanded in the drilling process by the aeronautic sector
One of the most important requirements within the aeronautical industry is to obtain lightweight structures to reduce carbon the difference between the mechanical properties of Ti6Al4V and carbon fiber reinforced plastics (CFRP) is desired for enhancing the strength and the lifetime of the aircraft components, it supposes a big challenge for achieving the high quality of the hole demanded in the drilling process by the aeronautic sector
The opposite is observed in CFRP material, i.e., the taper angle increased when it is located in the upper part of the stack

Summary

Introduction

The difference between the mechanical properties of Ti6Al4V and CFRP is desired for enhancing the strength and the lifetime of the aircraft components, it supposes a big challenge for achieving the high quality of the hole demanded in the drilling process by the aeronautic sector. When drilling CFRP material, many different defects can be produced, such as fiber pullout, fiber break-out, and/or delamination, which may cause the rejection of the pieces. In the aeronautical field, the percentage of pieces rejected because of delamination ascends to 60 % [1]. CFRP is a highly abrasive material and depending on the fiber orientation, it can cause a severe tool wear, which is accelerated when using high cutting speeds [2,3,4]. The burr formation is a troublesome in aerospace applications [6]

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Conclusion