Journal of Composite Materials-2015-Ghafarizadeh-0021998315587131

2011

Machining of fiber reinforced composites is an important activity in the integration of these advanced materials into engineering applications. Machining damage due to excessive cutting forces may result in rejecting the composite components at the last stages of their production cycle. Therefore, the ability to predict the cutting forces is essential for selecting process parameters that would result in minimum machining damage. In this paper, the effect of cutting conditions on cutting force are reviewed. In particular the aim in this work has been to investigate the relationship among the cutting force and surface roughness with the relevant cutting parameters, such as the cutting speed, axial depth of cut and the feed rate.

In this study, milling of a carbon-fiber-reinforced polymer composite material (CFRP) was investigated experimentally using various carbide end mills. The input parameters included the spindle speed, feed rate and cutting tool, whereas the output parameters were defined as the cutting force and surface roughness. The experimental design was based on the Taguchi L18 (6¹×3²) orthogonal array. In the tests, six different carbide end mills with a 10 mm diameter were used: an uncoated two-flute 30° helix-angled one; carbide-coated two-, three- and four-flute 30° helix-angled ones; and TiAl-coated three- and four-flute 45° helix-angled ones. The cutting parameters included three different feed rates (0.03, 0.06, 0.09) mm/tooth and three different spindle speeds (3800, 4800, 5800) min⁻¹. The Taguchi method was applied to select the most appropriate cutting parameters (cutting force, feed rate) for the tests. With the analysis of variance (ANOVA), the feed-rate factor was found to be the most effective one among these parameters (cutting forces and surface roughness). The results of the experiments showed that the uncoated carbide end mill had a better performance in terms of the cutting forces and surface roughness. Besides, it was also seen that the surface roughness increases with the increasing number of flutes and helix angle.

Acta Materialia Transylvanica

The use of fiber-reinforced plastics has increased significantly in the past decades. Consequently, the demand for finishing and machining of such materials has also escalated. During machining, the fiber-reinforced materials exhibit machining problems dissimilar to the problems of metals. These are fiber pull-out, fiber breakage in the cutting zone, matrix smearing and delamination. The purpose of this experiment is to investigate the characteristics of the resultant force (Fe) dur-ing the milling of carbon fiber reinforced plastic as a function of input machining parameters. For the force measurements, CFR with perpendicular (0°-90°) fiber orientation was machined. The experimental design involved the central composite design method. To analyze and evaluate the measurements, we applied the response surface methodology.

International Journal of Manufacturing Engineering, 2014

The machining of fibre reinforced composites is an important activity for optimal application of these advanced materials into engineering fields. During machining any excessive cutting forces have to be avoided in order to prevent any waste product in the last stages of production cycle. Therefore, the ability to predict the cutting forces is essential to select process parameters necessary for an optimal machining. In this paper the effect of cutting conditions during milling machining on cutting force and surface roughness has been investigated. In particular the cutting force components have been analysed in function of the principal process parameters and of the contact angle. This work proposes experimental models for the determination of cutting force components for CFRP milling.

2010

In the present study, an attempt has been made to investigate the influence of cutting speed, depth of cut, and feed rate on surface roughness during machining of 7075 Al alloy and 10 wt.% SiC particulate metal-matrix composites. The experiments were conducted on a CNC Turning Machine using tungsten carbide and polycrystalline diamond (PCD) inserts. Surface roughness of 7075Al alloy with 10 wt.% SiC composite during machining by tungsten carbide tool was found to be lower in the feed range of 0.1 to 0.3 mm/rev and depth of cut (DOC) range of 0.5 to 1.5 mm as compared to surface roughness at other process parameters considered. Above cutting speed of 220 m/min surface roughness of SiC composite during machining by PCD tool was less as compared to surface roughness at other values of cutting speed considered. Wear of tungsten carbide and PCD inserts was analyzed using a metallurgical microscope and scanning electron microscope. Flanks wear of carbide tool increased by a factor of 2.4 with the increase of cutting speed from 180 to 240 m/min at a feed of 0.1 mm/rev and a DOC of 0.5 mm. On the other hand, flanks wear of PCD insert increased by only a factor of 1.3 with the increase of cutting speed from 180 to 240 m/min at feed of 0.1 mm/rev and DOC 0.5 mm.

International Journal of Material Forming, 2018

CVD diamond-coated carbide tools could provide an economical alternative for trimming CFRPs components compared to their PCD tools counterpart. Nevertheless, there are still some technical issues to understand related to wear resistance and surface quality. In this work, a CVD tool with six straight flutes was used to investigate the relationship between surface roughness, surface damage, tool wear, cutting force and cutting parameters during the high speed trimming of CFRPs. Statistical techniques for identifying and selecting the best cutting conditions for CVD tool are developed. In terms of tool wear, results show that the best operational condition to minimize the tool wear is achieved at lower feed rates and higher cutting speeds. Experimental results show also that a 0°ply orientation represents the worst case and produces the maximum tool wear. Furthermore, a strong correlation between the feed force and the tool wear was observed. It was found that the surface roughness decreases as a reciprocal function of cutting length. This decrease was due to the matrix burning/sticking and the thermal damage related to the low thermal conductivity of CFRP. In such situation, R a becomes inappropriate indicator for roughness evaluation. On the other hand, it wasn't seen any type of delamination or fiber pull-out on the trimmed surface of all coupons for the three tool life tests. Accordingly, delamination can be avoided using high fixture rigidity, high quality of CFRP laminates, a suitable cutting tool and stable operational conditions.

Fibers

Carbon fiber-reinforced plastics (CFRP) have seen a significant increase in use over the years thanks to their specific properties. Despite continuous improvements in the production methods of laminated parts, a trimming operation is still necessary to achieve the functional dimensions required by engineering specifications. Laminates made of carbon fibers are very abrasive and cause rapid tool wear, and require high cutting temperatures. This creates damage to the epoxy matrix, whose glass-transition temperature is often recognized to be about 180 • C. This study aims to highlight the influence of the cutting temperature generated by tool wear on the surface finish and mechanical properties obtained from tensile tests. Trimming operations were performed on a quasi-isotropic 24-ply carbon/epoxy laminate, of 3.6 mm thickness, with a 6 flutes diamond-coated (CVD) cutter. The test specimens of 6 mm and 12 mm wide were obtained by trimming. The reduced width of the coupons allowed amplification of the effect of defects on the measured properties by increasing the proportion of coupon cross-section occupied by the defects. A new tool and a tool in an advanced state of wear were used to generate different cutting temperatures. Results showed a cutting temperature of 300 • C for the new tool and 475 • C for the worn tool. The analysis revealed that the specimens machined with the new tool have no thermal damage and the cut is clean. The plies oriented at −45 • presented the worst surface finish according to the failure mode of the fiber. For the worn tool, the surface was degraded and the matrix was carbonized. After cutting, observations showed a degraded resin spread on the machined surface, which reduced the surface roughness and hid the cutting defects. In support of these observations, the tensile tests showed no variation of the mechanical properties for the 12 mm-wide specimens, but did show a 10% loss in mechanical properties for the 6 mm-wide specimens. These results suggest that the thermal defects caused by tool wear affect tensile properties, but only from a certain coupon width below which the machining defects increase their influence on the properties.

Lecture Notes in Mechanical Engineering, 2019

Carbon fiber reinforced polymers (CFRPs) have found wide-ranging applications in numerous industrial fields especially in aerospace as well as automotive industries due to their excellent mechanical properties such as high strength, low weight and corrosion. The aim of the present work is to investigate the effect of machining parameters on surface quality and cutting forces in edge trimming process for a specific CFRP material. There were two variation of machining parameters focused in this work namely spindle speed (N) and feed per tooth (fz). The range of spindle speed applied was of 2506 rpm (low), 5012 rpm (moderate), and 7518 rpm (high) speed whilst for feed per tooth; 0.05, 0.1, and 0.15 mm/rev. The CFRP panel measured 3.25 mm in thickness and the type of fabric was unidirectional (UD) with 28 number of plies in total has been chosen to be the main study material. Router or burr tool geometry made of uncoated tungsten carbide with a diameter of 6.35 mm was used to perform th...

Journal of Materials Processing Technology, 1999

By virtue of their characteristics, the applications of composite materials based on carbon ®bre reinforced plastic (CFRP) have been increasing considerably. Thus new manufacturing process and production techniques must be developed to ensure high precision and good surface quality of the components. As a result of this manufacturing scenario, it is necessary to study the machining process. This work reports practical experiments in turning, to study the performance of different tool materials such as ceramics, cemented carbide, cubic boron nitride (CBN), and diamond (PCD). The results show that only diamond tools are suitable for use in ®nish turning. An optimisation methodology was used in rough machining to determine the best cutting conditions. The tests were carried out with cemented carbide tool at various cutting speeds. In the optimisation methodology were used the cutting length as the tool replacement criterion and some parameters were monitored such as the feed and cutting forces that can used be used as a safety system. Finally, it is concluded that the optimisation of the cutting conditions is extremely important in the selection of the tools and cutting conditions to be used in the CFRP manufacturing process. # 1999 Elsevier Science S.A. All rights reserved.