Machinability of Fiber-Reinforced Thermoplastics in Drilling

1993 ◽  
Vol 115 (1) ◽  
pp. 146-149 ◽  
Author(s):  
H. Hocheng ◽  
H. Y. Puw
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Tool Wear ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Steel ◽  
Fiber Reinforced ◽  
Heat Accumulation ◽  
Edge Quality ◽  
Carbon Fiber Reinforced

Polymer-based composite materials are used in a variety of industry. Recently, thermoplastic polymer suitable for the resinous matrix in carbon fiber-reinforced composites has been introduced for lower material and processing costs, improved damage tolerance and higher moisture resistance. The successful use of this material requires sophisticated production technology, however little reference of machining of thermoplastics composites can be found. The existing published results are almost exclusively for epoxy-based composite materials showing difficulty in avoiding poor finish, serious tool wear and delamination at hole entrance and exit due to the brittle material response to machining. Thermoplastics-based composite materials possesses better machinability. The current work reveals the machinability of an example of carbon fiber-reinforced ABS (Acrylonitrile Butadiene Styrene) in drilling compared to representative metals and thermoset-based composites. The observation of chips reveals that considerable plastic deformation is involved. Compared to the chip formation of thermoset plastics, it contributes to the improved edge quality in drilling. The edge quality is generally fine except in the case of concentrated heat accumulation at tool lips, which is generated by high cutting speed and low feed rate. Plastics tend to be extruded out of the edge rather than neatly cut. The average surface roughness along hole walls in commonly below one micron for all sets of cutting conditions in the experiment, values between 0.3 and 0.6 microns are typical. The high speed steel drill presents only minor tool wear during the tests. Based on these results, one concludes that the carbon fiber-reinforced ABS demonstrates good machinability in drilling.

High Speed Routing of Woven Carbon Fiber Reinforced Epoxy Laminates

2012 ◽  
Author(s):  
M. Meshreki ◽  
A. Sadek ◽  
M. H. Attia
Keyword(s):  
Surface Roughness ◽  
Carbon Fiber ◽  
Tool Wear ◽  
High Speed ◽  
Thermal Characteristics ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Axial Forces ◽  
Carbon Fiber Reinforced ◽  
Dimensional Errors

Little is known about the high speed routing of Carbon Fiber Reinforced Polymers (CFRP). Most of the work in the literature has focused on the drilling of CFRP. In this paper, an extensive experimental study has been conducted to better understand the dynamic, tribological, and thermal characteristics of high speed milling of CFRPs, in the range of 10,000 to 40,000 rpm (200 to 800 m/min, for 6.35 mm end-mill). The material used was a quasi-isotropic laminate comprising 35 plies of woven graphite epoxy. The tool wear was investigated on the flank and the rake faces. The machined slots were characterized in terms of straightness errors, dimensional errors, surface roughness, and delamination. The tool over-hang controls the tool dynamics, in this high speed range, and significantly affect various quality attributes of the produced holes; roughness, dimensional errors, and straightness. Similar trends were observed for the forces and the temperatures, whereby there is a given speed at which they reach a minimum and then they start to increase for higher speeds. The machining force and temperature trends with varying speeds and feeds are controlled by the chip load, the specific cutting pressures, and the effect of the frictional forces. The increased tool wear was found to directly affect the cutting forces and consequently lead to high delamination and surface roughness. The milled surface quality was mainly controlled by the feed rate. Limited surface delamination was observed due to the low axial forces associated with the routing process.

OPTIMIZATION OF DRILLING PROCESS ON CARBON-FIBER REINFORCED PLASTICS USING GENETIC ALGORITHM

2020 ◽  
pp. 2050056
Author(s):  
D. RAJ KUMAR ◽  
N. JEYAPRAKASH ◽  
CHE-HUA YANG ◽  
S. SIVASANKARAN
Keyword(s):  
Genetic Algorithm ◽  
Carbon Fiber ◽  
High Speed ◽  
High Speed Steel ◽  
Drilling Process ◽  
Regression Equations ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
Micro Drill

The usages of carbon-fiber reinforced polymer (CFRP) in aerospace, defense, and structural fields are increasing due to their excellent properties. However, the materials design, forming of material, machine tool and processing conditions are major tasks in manufacturing industries. Particularly, the micro feature making on macro-components using vertical machining center is a challenge nowadays. In this work, two different drill bits, such as high-speed steel (HSS) and solid carbide (SC) micro-drill, were used to make drilling on CFRP material. The performance of drills was evaluated by obtaining minimum delamination and stress in drilling by varying cutting velocity (CV), feed rate (FR), and air pressure (AP). Regression equations were formed according to the measured quality performance characteristics. The linear weighted method-based combined objective function algorithm and Genetic Algorithm was followed to multi-objective optimization. Besides, the most influencing factors were also identified and discussed using analysis of variance. The results explained that the SC micro-drill performance was better than HSS micro-drill. Also, the CV has the most eminent parameters followed by FR.

Wear Properties of Metal-Impregnated Carbon Fiber-Reinforced Carbon Composite Sliding Against a Copper Plate Under an Electric Current

2005 ◽  
Author(s):  
Shunichi Kubo ◽  
Hiroshi Tsuchiya
Keyword(s):  
Carbon Fiber ◽  
Electric Current ◽  
High Speed ◽  
Carbon Composite ◽  
Copper Plate ◽  
Fiber Reinforced ◽  
Wear Properties ◽  
Copper Disk ◽  
Carbon Fiber Reinforced ◽  
Arc Discharges

The metal-impregnated carbon fiber-reinforced carbon composite (C/C composite) is expected to be a candidate material for pantograph contact strips of high-speed electric railway vehicles, because its mechanical strength for flexure and impact is much higher than that of the conventional metal-impregnated carbon. The authors have investigated the wear properties of copper-titanium-alloy impregnated C/C composite sliding against a copper disk under an electric current and frequent arc discharges. The tested C/C composite was prepared by press molding and baking of laminated carbon fiber woven sheets. There exists anisotropy in the physical properties originated from the orientation of carbon fiber woven sheets lamination. The C/C composite was slid in two directions, in parallel with or perpendicular to the sheet layer. The test results show that the wear rate in sliding in the parallel direction exceeds that in the perpendicular direction, especially in the cases where the material is subjected to higher current density and more frequent arc discharges.

Experimental study on the picosecond pulsed laser cutting of carbon fiber-reinforced plastics

2018 ◽  
Vol 37 (15) ◽  
pp. 993-1003 ◽  
Author(s):  
Jun Hu ◽  
Dezhi Zhu
Keyword(s):  
Carbon Fiber ◽  
Bending Strength ◽  
Removal Rate ◽  
Cutting Speed ◽  
Pulsed Laser ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced

An experimental investigation of carbon fiber-reinforced plastics cutting with an Nd:YVO4 picosecond pulsed system was presented. One-factor experimental design was used in order to explain the influence of cutting parameters including laser power, hatch distance and cutting speed on the pulsed laser–material interaction. The process parameters were optimized by using central composite design of response surface methodology. The results in kerf width, taper angle, material removal rate, and heat-affected zones were discussed through the micrographs observed with optical microscope. Specimens were cut with three different tools: picosecond pulsed laser, nanosecond pulsed laser, and conventional cutting, and the tensile strength and bending strength tests were conducted. Furthermore, the effect of the heat-affected zones on the static strength was also analyzed.

scholarly journals Chip Morphology and Delamination Characterization for Vibration-Assisted Drilling of Carbon Fiber-Reinforced Polymer

2019 ◽  
Vol 3 (1) ◽  
pp. 23 ◽  
Author(s):  
Ramy Hussein ◽  
Ahmad Sadek ◽  
Mohamed Elbestawi ◽  
M. Attia
Keyword(s):  
Carbon Fiber ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Polymers ◽  
Geometrical Accuracy ◽  
Carbon Fiber Reinforced

Carbon fiber-reinforced polymers (CFRP) are widely used in the aerospace industry. A new generation of aircraft is being built using CFRP for up to 50% of their total weight, to achieve higher performance. Exit delamination and surface integrity are significant challenges reported during conventional drilling. Exit delamination influences the mechanical properties of machined parts and, consequently, reduces fatigue life. Vibration-assisted drilling (VAD) has much potential to overcome these challenges. This study is aimed at investigating exit delamination and geometrical accuracy during VAD at both low- and high-frequency ranges. The kinematics of VAD are used to investigate the relationship between the input parameters (cutting speed, feed, vibration frequency, and amplitude) and the uncut chip thickness. Exit delamination and geometrical accuracy are then evaluated in terms of mechanical and thermal load. The results show a 31% reduction in cutting temperature, as well as a significant enhancement in exit delamination, by using the VAD technology.

Damage detection of unidirectional carbon fiber–reinforced laminates with embedded magnetostrictive particulates: A preliminary study

2012 ◽  
Vol 24 (8) ◽  
pp. 991-1006 ◽  
Author(s):  
Oliver J Myers ◽  
George Currie ◽  
Jonathan Rudd ◽  
Dustin Spayde ◽  
Nydeia Wright Bolden
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Nondestructive Evaluation ◽  
Composite Laminates ◽  
Composite Structures ◽  
Single Layer ◽  
Polymeric Composite ◽  
Analytical Models ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced

Defects in composite laminates are difficult to detect because of the conductive and paramagnetic properties of composite materials. Timely detection of defects in composite laminates can improve reliability. This research illustrates the preliminary analysis and detection of delaminations in carbon fiber laminate beams using a single layer of magnetostrictive particles and noncontacting concentric magnetic excitation and sensing coils. The baseline analytical models also begin to address the intrusive nature of the magnetostrictive particles as well as relate the applied excitation field with the stress and magnetic flux densities induced in the magnetostrictive layer. Numerical methods are used to begin to characterize the presence of magnetostrictive particles in the laminate and the behavior of the magnetostrictive particles in relationship to the magnetic field used during sensing. Unidirectional laminates with embedded delaminations are used for simulations and experimentations. A novel, yet simplified fabrication method is discussed to ensure consistent scanning and sensing capabilities. The nondestructive evaluation scanning experiments were conducted with various shapes and sizes of damages introduced into carbon fiber–reinforced polymeric composite structures. The results demonstrate high potential for magnetostrictive particles as a low-cost, noncontacting, and reliable sensor for nondestructive evaluation of composite materials.

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