Peck drilling of CFRP/titanium stacks: effect of tool wear on hole dimensional and geometrical accuracy

Prisco, Umberto; Impero, Filomena; Rubino, Felice

doi:10.1007/s11740-019-00915-1

Cited by 19 publications

(5 citation statements)

References 33 publications

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“…It appears to contrast to the findings in Reference [ 8 ] that the hole diameter oversize mostly rises with a feed rate increase. In Reference [ 54 ], it was reported that the deviation of hole diameter could be reduced up to 60 µm in CFRP and Ti alloy layers by utilizing peck drilling techniques in combination with the MQL technique. It creates favorable conditions for chip crushing and minimizes heat generation in the interface tool-workpiece zone.…”

Section: Resultsmentioning

confidence: 99%

Experimental Study of Drilling Temperature, Geometrical Errors and Thermal Expansion of Drill on Hole Accuracy When Drilling CFRP/Ti Alloy Stacks

et al. 2020

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The drilling of holes in CFRP/Ti (Carbon Fiber-Reinforced Plastic/Titanium alloy) alloy stacks is one of the frequently used mechanical operations during the manufacturing of fastening assemblies in temporary civil aircraft. A combination of inhomogeneous behavior and poor machinability of CFRP/Ti alloy stacks in one short drilling brought challenges to the manufacturing community. The impact of the drilling temperature and time delay factor under various cutting conditions on hole accuracy when machining CFRP/Ti alloy stacks is poorly studied. In this paper, the drilling temperature, the phenomenon of thermal expansion of the drill tool, and hole accuracy are investigated. An experimental study was carried out using thermocouples, the coordinate measuring machine method, and finite element analysis. The results showed that the time delay factor varied from 5 (s) to 120 (s), influences the thermal-dependent properties of CFRP, and leads to an increase in hole roundness. Additionally, the thermal expansion of the drill significantly contributes to the deviation of the hole diameter in Ti alloy.

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Section: Resultsmentioning

confidence: 99%

Experimental Study of Drilling Temperature, Geometrical Errors and Thermal Expansion of Drill on Hole Accuracy When Drilling CFRP/Ti Alloy Stacks

et al. 2020

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“…Furthermore, most contributions dealing with the working temperature in the drilling of hybrid metal/composite laminates focused on stacked composites, where a CFRP-or GFRP laminate is joined with a single metallic (usually titanium or aluminum alloy) plate. [24][25][26] Nevertheless, working temperatures arising during the machining of fiber metal laminates can play a key role on the quality of the holes. High temperatures, indeed, may cause the burnout of the polymeric resin, if they go above the thermal degradation limit, unwanted dimensional alterations, acceleration of fiber pull-out and tool wear.…”

Section: Introductionmentioning

confidence: 99%

Temperature analysis in fiber metal laminates drilling: Experimental and numerical results

et al. 2022

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Drilling process of fiber metal laminates (FML) requires a proper design of the processing parameters to prevent the occurrence of several issues and minimize defects, which can be detrimental for the integrity of the parts. These aspects become more critical in dry machining used in aeronautic field. In this scenario, the monitoring of process temperature is crucial to obtain useful information for machining optimization since many critical factors, such as matrix burnout, fiber pull‐out and delamination, depend on the heat generated during the machining. The aim of this work is to monitor the temperature measured on the tool and workpiece during dry drilling of Al/GFRP (GLARE) and Al/CFRP (CARALL) hybrid laminates. The influence of the cutting speed on the temperature trends was analyzed. Two different set‐ups were designed to measure the temperature on the tool, near the cutting edge and on the flank, and inside the laminate, in both the metallic and the composite parts. In addition, a numerical model to analyze the process temperature trend during drilling has been developed. The increasing the spindle speed from 1500 to 8000 rpm resulted in a decreasing of maximum temperatures of approximately 10°C on the tool tip and on the flank for the GLARE, and of almost 20°C in the CARALL laminates. The numerical simulation also pointed that the temperature fields is dictated by the thermal properties of carbon and glass fibers: temperature profiles within the CARALL were found smoother than those observed in GLARE.

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“…Alonso et al investigated the effect of flute number and stepped tip design [24]. In a study by Prisco et al, the effect of tool wear on the dimensional and geometric accuracy of machined holes was investigated in pecking drilling of CRFP and Ti stacks [25]. The surface integrity was evaluated by Kuo et al Ti-6Al-4V/CFRP/Al-7050 stack was drilled using a CVD diamond coated tool [26].…”

Section: Introductionmentioning

confidence: 99%

Evaluation and multi-criteria optimization of surface roughness, deviation from dimensional accuracy and roundness error in drilling CFRP/Ti6Al4 stacks

Motorcu¹,

Eki̇ci̇²

2022

FME Transactions

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In this study, machinability tests were carried out to investigate the effects of control factors (cutting tool geometry, cutting speed, and feed rate) on the surface roughness (Ra), deviation from dimensional accuracy (Da_dev), roundness error (Re) in drilling CFRP/Ti6Al4V mixed metallic stack and to determine the optimum levels of drilling parameters. The effects of each control factor and their interactions on three quality characteristics were analyzed, and their levels were single-objectively optimized for each component material by the Taguchi method. The material has components (CFRP and Ti6Al4V) with essentially different properties (mechanical, physical, machinability). Single-objective optimization has limited usability as the drilling must be performed in one through both layers. Therefore, in an additional step, the optimum levels of the control factors were determined by optimizing multi-objective with the Additive Ratio Assessment (ARAS) method. Higher Ra, Da_dev, and Re values were obtained on the CFRP component compared to the Ti6Al4V component. The CFRP/Ti6Al4V stack should be drilled with a nano fire coated carbide drill (T3) at medium cutting speed and high feed rate to achieve minimum Ra, Da_dev, and Re values in one go.

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Peck drilling of CFRP/titanium stacks: effect of tool wear on hole dimensional and geometrical accuracy

Cited by 19 publications

References 33 publications

Experimental Study of Drilling Temperature, Geometrical Errors and Thermal Expansion of Drill on Hole Accuracy When Drilling CFRP/Ti Alloy Stacks

Experimental Study of Drilling Temperature, Geometrical Errors and Thermal Expansion of Drill on Hole Accuracy When Drilling CFRP/Ti Alloy Stacks

Temperature analysis in fiber metal laminates drilling: Experimental and numerical results

Evaluation and multi-criteria optimization of surface roughness, deviation from dimensional accuracy and roundness error in drilling CFRP/Ti6Al4 stacks

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