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Carbon fiber-reinforced plastics (CFRP) composites are difficult-to-machine materials due to extensive tool wear. This article investigates the impact of carbon fiber types on tool wear in edge-trimming CFRPs, each with the ply angle of 0 deg, 45 deg, 90 deg, or 135 deg, using uncoated tungsten carbide endmills at the high spindle speed of 6000 rpm and the constant feed of 0.0508 mm/rev. Three distinct types of carbon fiber tows, including T300 as standard modulus (SM), IM-7 as intermediate modulus (IM), and K13312 as high modulus (HM), have been vacuum infused into CFRP laminates and edge trimmed to investigate wear characteristics. Three wear criteria measured are flank wear, edge rounding radii, and worn area. The results show that tool wear is influenced by carbon fiber properties, such as fiber tensile strength, tensile modulus, and fiber microstructure. Overall, IM carbon fibers with the highest tensile strength produced the most extensive tool wear due to the abrasive carbon fibers. Of four fiber directions, the largest tool wear was obtained from the 45 deg angle, while the lowest tool wear occurred in the 0 deg angle. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymer (CFRP) composites are widely used in the aerospace field because of their outstanding lightweight material characteristics, tensile strength, and stiffness properties. The tools used in composite machining exhibits different cutting performance and machining quality under different cutting conditions. The combination of tool material, tool geometry, and cutting conditions strongly influence the tool life and surface quality of the machined parts. Edge trimming of CFRP blanks with tungsten carbide two flute end mill cutter was conducted. The operation was carried out on a computer numerical control (CNC) router by varying cutting speed, feed speed, and depth of cut. Experimental results indicated that the wear of carbide tools is characterized by abrasive wear and rounding of the cutting edge. This occurred mainly by hard abrasion of the carbide grains. Tool life was observed to be inversely proportional to cutting speed, feed speed, and depth of cut. An expanded tool wear equation with power, average temperature, and resultant force as independent variables provided higher tool wear predictive capabilities. To check the adequacy of the regression model, validation runs were conducted. The experimental tool wear obtained from validation experiments were compared with the tool wear obtained using regression. An approximate average error of 5 % confirms that the experimental and regression tool wear values are very close. The equations and analysis permit trimming of CFRP to be designed such that tool wear is optimized and well forecasted. [ABSTRACT FROM AUTHOR]

Machining of CFRP composites is usually described as a challenging process from tool life and surface quality perspectives. To achieve a flawless machined surface at reasonable cutting tool life/cost, an optimum combination of cutting tool material and geometry is the key. The cutting tool angles are of importance as these dictate the cutting mechanism as well as the cutting edge robustness and the introduction of vibration to the machining process opens up new horizons of improvement and stirs further research questions. This article investigates the effect of tools with different geometry possessing different rake angles when used in ultrasonic-assisted edge trimming operation dealing with multidirectional CFRP laminates. A full-factorial experimental design was adopted to analyze the effect of process parameters typically cutting speed, feed rate, rake angle, amplitude, and their interactions. Machining performance indicators were captured which were the cutting forces, tool wear, chip temperature, and surface roughness. The results showed that UAM mode contributed to an increase in the cutting forces, tool wear, and chip temperature compared to the conventional mode. On the other hand, UAM mode improved the quality of the machined surface. Additionally, the ultrasonic mode enhanced the material removal mechanism using a tool with a negative rake angle. [ABSTRACT FROM AUTHOR]

Recently, the use of carbon fibre reinforced polymer (CFRP) composites is predominant and will grow further. Although these fibrous composites are often manufactured near net shape, their mechanical machining is often required to meet dimensional tolerances. Considering the difficult-to-cut nature of CFRP composites, the technology planning of edge trimming of CFRPs poses significant challenges and obstacles. Therefore, the main aim of this study is to critically review and discuss challenges, recent expertise and experience gained in the area of edge trimming CFRPs. On the one hand, conventional and advanced edge trimming technologies are reviewed and compared. On the other hand, advanced cutting tools are presented and discussed. Finally, future scope and prospects are highlighted to determine further research scopes in the edge trimming of CFRP composites. [ABSTRACT FROM AUTHOR]

The main aim of this work was to investigate the effect of machining conditions namely cutting speed (Vc) and feed per tooth (fz) towards the surface finish during the edge trimming process on a specific CFRP material. The range of cutting speed (Vc) applied was 50 m/min (low), 100 m/min (middle) and 150 m/min (high) whilst for the feed per tooth (fz); 0.05 mm (low), 0.10 mm (middle) and 0.15 mm (high). The CFRP panel is measured 3.25 mm in thickness and has 28 plies in total. Router or burr tool made of uncoated tungsten carbide with a diameter of 6.35 mm is used to perform the edge trimming process. The Taguchi technique has been adopted to plan the overall experimental process. Surface roughness measurement was taken using Mitutoyo Surftest SJ-410 and optical microscope Nikon MM-800 is utilized to further observe the quality of the trimmed surfaces. From the ANOVA analysis, both factors namely cutting speed, Vc and feed per tooth, fz indicated a significant result towards the surface finish of the trimmed surfaces. The result is supported by the observation via optical microscopy which clearly exhibits uncut fibers, fiber pull-out and matrix degradation conditions. Detailed results are elaborated and discussed further in this paper. [ABSTRACT FROM AUTHOR]

A main requirement in the field of polymer composites milling with fibre reinforcement is to machine with high quality in one operation (without delamination or burrs). That requires precise selection of cutting tool geometry and cutting conditions. Fibre-reinforced plastics (FRPs) are difficult-to-machine materials due to high abrasivity, relatively low melting point of polymeric matrices and inclination to delamination or large burr formation. This study investigates the main factors influencing the forces, temperature and surface quality in terms of the cutting conditions through ANOVA testing. Machining during this experiment was performed with a polycrystalline diamond (PCD) end mill. Next, the strongest factor with various double-helix cutting tool geometry was compared. The geometric model of the cutting forces was created based on previous measurements as well as a general empirical model of cutting forces, temperature on the machined surface and average delamination length for C/PPS material. [ABSTRACT FROM AUTHOR]

Highlights • Tool wear is influenced most by the feed speed and the depth of cut. • TOPSIS optimization works well in combination with neural networks generalization. • Sensor infusion in the neural networks training vector improves data generalization. • Optimum cutting conditions consisted of (N4000 rpm, F1000 mm/min, D2.5 mm). Abstract This work presents the results of an optimization study of trimming carbon fiber composite by technique of order preference by similarity to ideal solution (TOPSIS). Edge trimming was conducted at different levels of cutting speed, feed speed, and radial depth of cut using a 2 k factorial design. The effects of cutting parameters on tool wear, surface roughness and tool temperature were analyzed and discussed. Data generalization was performed by training multiple neural network structures (NN) where the input vector of the neural networks contained sensor data in addition to typical process parameters. TOPSIS was used to select the optimal cutting conditions that could generate minimum tool wear, surface roughness, and tool temperature simultaneously while maintaining high production rates. The results show that the NN models offer better results when sensor data is fused in the input vector. TOPSIS optimum conditions were confirmed by validation experiments and were found to be accurate. [ABSTRACT FROM AUTHOR]

The superior properties make carbon fiber-reinforced plastic (CFRP) composites attractive in many applications. After CFRPs’ molding processes, additional machining processes are needed to produce final functional shapes with dimensional precision. Edge trimming is the primary process to cut the edge of CFRP composites. To reduce or further solve the problems in traditional machining processes, edge trimming of CFRP composites with rotary ultrasonic machining (RUM) has been proposed and conducted in this investigation. In RUM edge trimming processes, two different tool orientations (RUM edge trimming with tool end face and RUM edge trimming with tool side face) can be performed. The comparisons of machining performance and machined surface quality between these two different RUM edge trimming processes have been conducted. Smaller ultrasonic vibration amplitude in RUM using tool end face or larger ultrasonic vibration amplitude in RUM using tool side face produces smaller surface roughness. Lower feeding-directional cutting force, lower normal cutting force, and lower resultant force are generated in the process using tool side face. RUM using tool end face produces smaller surface roughness, smaller debris width, microcracking, flowed matrix on machined CFRP surfaces, etc. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced plastics (CFRPs), have excellent mechanical properties such as high modulus, fatigue strength and specific tensile strength have increasingly been used in various applications. Although the CFRP components are made to near net shape using different composite moulding techniques, the components are needed to be machined with some post machining processes like edge trimming. Edge trimming is normally done with end mills of different geometry and materials. The quality of the trimmed edges and life of the tool used depend on the type of tool material and tool geometry and cutting parameters. In this paper, coated router tools (also called as burr tools) with typical geometry have been selected for studying the surface roughness of CFRP work material and tool wear. The study was done with three types of tungsten carbide router tools namely uncoated carbide, AlTiN (Aluminium Titanium Nitrate) coated carbide, DLC (Diamond Like Carbon) coated carbide. Due to the complexity of geometry, the tool wear of this kind of router tool was indirectly monitored and measured using the acoustic emission (AE) signals. The optimization was done by considering the multiple objectives of minimum surface roughness and minimum tool wear using two different optimization techniques namely genetic and differential algorithms. The salient parameters which are considered for optimization are spindle speed, feed rate and coating material. A comparison study of the optimized results obtained from both of these optimization techniques with experimental results has been madein order to identify their suitability for using for optimization in machining of CFRP materials. [ABSTRACT FROM AUTHOR]

Delamination occurs in edge trimming of CFRP on the surface plies due to lack of support and is known to depend on feed rate, cutting speed, and tool wear. Burr tools have complex geometries with ill-defined cutting edges and surfaces, and the traditional method of wear measurement is not readily applicable to them. This paper presents and discusses an alternative method for defining tool life for tools with complex geometries, and the application of this method to burr tools is demonstrated. The approach relies on the effect of tool deterioration, rather than the physical wear itself, to define a tool life criterion and a tool life equation. In this study, an indirect technique is used to quantify the tool wear based on delamination. The damage caused by delamination on the composite material undergoing edge trimming operation is quantified in terms of delamination depth and frequency of occurrence per given length. A proper tool life criterion is then defined based on acceptable industry practices, and an empirical tool life equation was developed as a function of cutting speed and feed rate. The new tool life equation was validated by experiments. [ABSTRACT FROM AUTHOR]

Characterization of the damage induced by machining of fibre-reinforced composites is usually performed by measuring surface roughness. Contact-based surface profilometers are the most used equipment in industry; however, it has been found that there are performance limitations which may result when used to measure machined heterogeneous composite surfaces. In this research, surface roughness is characterised using a commercial non-contact optical method, and compared with a conventional stylus profilometer. Unidirectional and multidirectional carbon fibre laminates were edge trimmed and slot milled. The variation in surface roughness was compared using different tool types, fibre orientations and cutting parameters. Surface damage and cutting mechanisms were assessed by using scanning electron microscope images, and the suitability of roughness parameters were also analysed including: Sa, Skewness and Kurtosis. Using the optical system allowed accurate roughness calculation of individual plies on a multidirectional laminate with different fibre orientations. The research has also shown that the optical system, including the use of areal roughness parameters, can increase the accuracy of roughness measurement for machined fibrous composite surfaces and is less sensitive to measurement position than the stylus. [ABSTRACT FROM AUTHOR]

The impact of the edge trimming process on permanently bonded wafers is described. The edge trimming process is a blade sawing process applied on the Si wafer edge and bevel, removing the fragile edge of the wafer prior to grinding. We investigated two routes for the integration on permanently bonded Si wafers, edge-trim before bonding and edge-trim after bonding. The impact on the subsequent processes for both integration routes is assessed. For the case of edge-trim before bonding, a combination of functional water cleaning such as ozone dissolved in water and ammoniac scrub cleaning shows a significant effect to remove Si residues, enabling void free dielectric bonding. For the case of edge-trim after bonding, utilizing a small grit diamond blade shows no mechanical failures into the dielectric bonding interface. These proposed processes are a very promising for the fabrication of extreme thinned Si without mechanical failure at wafer edge. [ABSTRACT FROM AUTHOR]

Delamination is one of the main problems that occur when machining fiber-reinforced composite materials. In this work, Types I and II of delamination are studied separately in edge trimming of basalt fiber reinforced plastic (BFRP). For this purpose, one-dimensional and area delamination parameters are defined. One-dimensional parameters (Wa and Wb) allow to know average fibers length while the analysis of area delamination parameters (Sd) allow to evaluate delamination density. To study delamination, different tests are carried out modifying cutting parameters (cutting speed, feed per tooth and depth of cut) and material characteristics (fiber volume fraction and fiber orientation). Laminates with a lower fiber volume fraction do not present delamination. Attending to one-dimensional parameters it can be concluded that Type II delamination is more important than Type I and that a high depth of cut generates higher values of delamination parameters. An analysis of variance (ANOVA) is performed to study area parameters. Although delamination has a random nature, for each depth of cut, more influence variables in area delamination are firstly, feed per tooth and secondly, cutting speed. [ABSTRACT FROM AUTHOR]

Although there are many machining studies of carbon and glass fiber reinforced plastics, delamination and tool wear of basalt fiber reinforced plastics (BFRP) in edge trimming has not yet studied. This paper presents an end milling study of BFRP fabricated by resin transfer molding (RTM), to evaluate delamination types at the top layer of the machined edge with different cutting conditions (cutting speed, feed rate and depth of cut) and fiber volume fraction (40% and 60%). This work quantifies delamination types, using a parameter Sd/L, that evaluates the delamination area (Sd) and the length (L), taking into account tool position in the yarn and movement of yarns during RTM process, which show the random nature of delamination. Delamination was present in all materials with 60% of fiber volume. High values of tool wear did not permit to machine the material due to an excessive delamination. Type II delamination was the most usual delamination type and depth of cut has influence on this type of delamination. [ABSTRACT FROM AUTHOR]