Optimization and sensitivity analysis of drilling parameters for sustainable machining of carbon fiber–reinforced polypropylene composites

2018 ◽  
Vol 32 (11) ◽  
pp. 1485-1508 ◽  
Author(s):  
M Mudhukrishnan ◽  
P Hariharan ◽  
K Palanikumar ◽  
B Latha

Machining processes face two major challenges: sustainability and cleaner production. However, the effective utilization of tool and methods of lubrication system in sustainable machining have been dealt in depth in earlier investigations. This work aims to optimize sustainable machining parameters in drilling process for recyclable carbon fiber-reinforced polypropylene (CFR-PP) composites. This work is focused on modeling and optimization of drilling parameters for sustainable machining with respect to thrust force and torque for CFR-PP composites. The response surface method based on D-optimal design of experiments is used for modeling and optimization with variables such as drill spindle speed and drill feed rate as numerical factors, which includes different drill material as the categorical factor. The influences of tool materials on the sustainable machining are also discussed in detail. Further, the sensitivity analysis is applied to compare the relative impact of control parameters (spindle speed, feed rate, and drill materials) on thrust force and torque. The scanning electron microscope images are used for analyzing the morphologies of drilled surfaces.

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540031 ◽  
Author(s):  
Cheng-Dong Wang ◽  
Kun-Xian Qiu ◽  
Ming Chen ◽  
Xiao-Jiang Cai

Carbon Fiber Reinforced Plastic (CFRP) composite laminates are widely used in aerospace and aircraft structural components due to their superior properties. However, they are regarded as difficult-to-cut materials because of bad surface quality and low productivity. Drilling is the most common hole making process for CFRP composite laminates and drilling induced delamination damage usually occurs severely at the exit side of drilling holes, which strongly deteriorate holes quality. In this work, the candle stick drill and multi-facet drill are employed to evaluate the machinability of drilling T700/LT-03A CFRP composite laminates in terms of thrust force, delamination, holes diameter and holes surface roughness. S/N ratio is used to characterize the thrust force while an ellipse-shaped delamination model is established to quantitatively analyze the delamination. The best combination of drilling parameters are determined by full consideration of S/N ratios of thrust force and the delamination. The results indicate that candle stick drill will induce the unexpected ellipse-shaped delamination even at its best drilling parameters of spindle speed of 10,000 rpm and feed rate of 0.004 mm/tooth. However, the multi-facet drill cutting at the relative lower feed rate of 0.004 mm/tooth and lower spindle speed of 6000 rpm can effectively prevent the delamination. Comprehensively, holes quality obtained by multi-facet drill is much more superior to those obtained by candle stick drill.


2014 ◽  
Vol 697 ◽  
pp. 62-66
Author(s):  
Hong Fei Wang ◽  
Hua Zhou Li ◽  
Long Sheng Lu ◽  
Ying Xi Xie ◽  
Yu Xiao

Due to its excellent performance, carbon fiber-reinforced plastics (CFRP) have been widely applied in industrial applications. The phenomenon of delamination can readily occur when drilling CFRP composites, which affects the quality of drilling holes. To effectively control the generation of processing defects, this paper focused on the analysis of the thrust force and the delamination factor. The delamination analysis was performed using graphs of the spindle speed, feed rate and drill diameter as independent parameters. The results suggest that there was a positive correlation between the delamination factor Fd and the thrust force Fz. The delamination factor decreases with increases in the spindle speed and increases with increases in the feed rate or with increases in the drill diameter. Based on the experimental data, this paper established a formula model of the delamination factor Fd, which would promote the further study of drilling CFRP composites.


Author(s):  
Tarakeswar Barik ◽  
Kamal Pal ◽  
Smruti Parimita ◽  
Priyabrata Sahoo ◽  
Karali Patra

Fiber-reinforced plastic is one of the top priorities lightweight materials with excellent mechanical properties for the aerospace industries in recent years. However, it is difficult to machine despite having unique properties due to its non-homogeneous and abrasive nature in alternate fiber and matrix layers. Thus, it is found to be a challenging task to drill hole on such hard-to-machine materials, which is highly essential for the development of most of the engineering structural components. The present work addresses various drilling-induced defects such as delamination, circularity error, and roughness variations in the hole surface during drilling of quasi-isotropic cross-fiber oriented bi-directional woven-type carbon fiber reinforced plastic laminate using a full factorial design of experiments for different drill geometry. The response surface methodology was considered for the regression model development, which was found to be highly significant. The machining forces with associated torque have also been acquired during drilling, which was divided and further analyzed in time domain to correlate with drilling flaws. The drilling-induced delamination was found to be higher at a high feed rate using a higher drill point angle due to substantial thrust force generation at the initial stages in the drilling cycle. However, the internal surface finish with associated circularity error was reduced for higher spindle speed with less feed rate using a low drill point angle because of low torque fluctuation at the final drilling phases. The axial thrust force was found to be a prime indicator of drilled hole surface delamination, whereas drilling torque precisely indicated internal surface roughness as well as circularity error. The global root mean square, along with a local peak of thrust and torque, both were highly essential to completely characterize the drilled hole quality.


2021 ◽  
Author(s):  
Amin Moghaddas

Abstract In this study, a special resolution V design and Response surface methodology (RSM) were used to characterize the ultrasonic-assisted drilling (UAD) process of Aluminum 6061. This characterization was done through developing mathematical models to study the effect of ultrasonic and drilling parameters including spindle speed, feed rate and amplitude on thrust force, temperature, chip morphology and power. The tests were done using an industrially hardened non-rotating UAD system mounted in a CNC turning center. The analysis of variance (ANOVA) was used to find significant parameters of thrust force, temperature, chip morphology and power. Then, for all responses, the optimum drilling parameters that provide desired solutions for all responses were obtained. This was followed by out-of-sample testing to verify the accuracy of the developed models. The results of this study showed that in UAD of aluminum, the minimum values of thrust force and chip size were obtained at low spindle speed, low feed rate and high amplitude. The results also showed that amplitude was not a significant parameter affecting the tool temperature and cannot be used to analyze the effect of ultrasonic vibrations on generated heat during UAD. Instead, the interaction of amplitude and feed rate was significant and should be considered in the analysis. Finally, minimum consumed power, specially at higher amplitudes, can be obtained using high spindle speed and low feed rate.


2010 ◽  
Vol 638-642 ◽  
pp. 927-932 ◽  
Author(s):  
M.A. Azmir ◽  
Praveena Nair Sivasankaran ◽  
Z. Hamedon

This thesis deals with carbon fiber reinforced plastics (CFRP) composites, an advanced material which is widely used in manufacturing aircrafts because of their unique mechanical and physical properties. The research mainly involved drilling of CFRP. This study is focused on analyzing the thrust force and delamination against drilling parameters namely feed rate, spindle speed and type of tool materials. Also, the optimal parameters were chosen using an optimization method called D optimal. It was observed that the higher the feed rate and spindle speed employed, the higher the thrust force and delamination occur. The split point fibre (SPF) drill gave the lowest values of thrust force and delamination. Based on the optimal parameters, a verification test was conducted and the prediction error was 2.3% and 5.6% for thrust force and delamination respectively. This shows, that the optimal parameters obtained is reliable as it could improve the process considerably. The results of this study could be used as a reference for further research and studies on drilling of CFRP.


2008 ◽  
Vol 375-376 ◽  
pp. 236-240 ◽  
Author(s):  
Chung Chen Tsao

Twist drill is widely used in hole-making process in industries, due their low production cost and ease of regrinding after wear. However, drilling of fiber reinforced plastics with twist drill often results in defects and damages, such as delamination, debonding, spalling and fiber pullout. The chisel edge of twist drill is the mainly influence for the thrust force and the hole quality in drilling carbon fiber reinforced plastic (CFRP) laminates. Pre-drilled pilot hole or reduce chisel edge can eliminate the threat for twist drill in drilling induced-delamination. Drilling-induced thrust force was selected as quality character factors to optimize the drilling parameters (drill type, feed rate and spindle speed) to get the smaller the better machining characteristics by Taguchi method. The results show that the feed rate and drill type are the most significant factor affecting the induced-thrust in drilling CFRP laminates.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5457
Author(s):  
Fu-Ji Wang ◽  
Meng Zhao ◽  
Jian-Bo Yan ◽  
Shen Qiu ◽  
Xin Liu ◽  
...  

Aramid fiber-reinforced plastic (AFRP) is widely used in bullet-proof and armor structures, and is difficult to drill because of the high-toughness aramid fibers with ductile fracturing—differently from carbon fiber. Therefore, drilling quality cannot be ensured by the drilling used for carbon fiber-reinforced plastic, and frequently, delamination and burrs occur in the drilling process. This article first established a two-dimensional cutting model for analyzing the fiber deformation and material interface cracking. According to the model, reducing the thrust force and the radial force of the edge on the fibers is an effective way to reduce the fiber deformation, and a three-point step drill is proposed further. Comparative experiments were carried out among twist drilling, candle core drilling and three-point step drilling under three drilling parameters. The results show that the three-point step drill changed the traditional cutting behavior on the drill-exit material into a compound process. Finally, the AFRP was cut effectively with the novel drill with a small thrust force, and the delamination and “burrs area” were reduced through different drilling parameters. In summary, the three-point step drill can drill the AFRP without delamination and burrs with 0.02 mm/rev, which provides a new solution of cost-effective production for AFRP manufacturers.


2021 ◽  
Vol 5 (7) ◽  
pp. 189
Author(s):  
Muhammad Hafiz Hassan ◽  
Jamaluddin Abdullah ◽  
Gérald Franz ◽  
Chim Yi Shen ◽  
Reza Mahmoodian

Drilling two different materials in a layer, or stack-up, is being practiced widely in the aerospace industry to minimize critical dimension mismatch and error in the subsequent assembly process, but the compatibility of the drill to compensate the widely differing properties of composite is still a major challenge to the industry. In this paper, the effect of customized twist drill geometry and drilling parameters are being investigated based on the thrust force signature generated during the drilling of CFRP/Al7075-T6. Based on ANOVA, it is found that the maximum thrust force for both CFRP and Al7075-T6 are highly dependent on the feed rate. Through the analysis of maximum thrust force, supported by hole diameter error, hole surface roughness, and chip formation, it is found that the optimum tool parameters selection includes a helix angle of 30°, primary clearance angle of 6°, point angle of 130°, chisel edge angle of 30°, speed of 2600 rev/min and feed rate of 0.05 mm/rev. The optimum parameters obtained in this study are benchmarked against existing industry practice of the capability to produce higher hole quality and efficiency, which is set at 2600 rev/min for speed and 0.1 mm/rev for feed rate.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.


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