Precision Hole Making on Laminates Composite: Comparison between Drilling and Punching

2016 ◽  
Vol 857 ◽  
pp. 291-295 ◽  
Author(s):  
A.B. Abdullah ◽  
N.A. Ghaffar ◽  
Z. Samad
Keyword(s):  
Structural Material ◽  
Tool Wear ◽  
Measurement Method ◽  
Surface Measurement ◽  
Optical Surface ◽  
Hole Quality ◽  
Hole Making ◽  
Scanned Images ◽  
Precision Hole

Accurate and strong fastener assembly depends on precision of the hole. For structural material likes composites, these criteria is very important. Drilling is the most common method in producing hole on composites. But the main problem of drilling is excessive tool wear that may affect the quality of the holes. Punching is another alternative in making a hole. The main objective of this study is to compare between drilling and punching in terms of hole quality. The scanned images of the produced hole will be captured using commercial 3D optical surface measurement method namely Alicona IFM. The effect to the quality of the produced hole will be measured and compared between drilling and punching.

scholarly journals Between-the-Holes Cryogenic Cooling of the Tool in Hole-Making of Ti-6Al-4V and CFRP

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 795 ◽  
Author(s):  
Asif Iqbal ◽  
Guolong Zhao ◽  
Juliana Zaini ◽  
Munish Kumar Gupta ◽  
Muhammad Jamil ◽  
...  
Keyword(s):  
Tool Wear ◽  
Thrust Force ◽  
High Strength ◽  
Cryogenic Cooling ◽  
Specific Cutting Energy ◽  
Hole Quality ◽  
Lightweight Materials ◽  
Cutting Energy ◽  
Structural Applications ◽  
Hole Making

Lightweight materials are finding plentiful applications in various engineering sectors due to their high strength-to-weight ratios. Hole-making is an inevitable requirement for their structural applications, which is often marred by thermal damages of the drill causing unacceptable shortening of tool life. Efficient cooling of the tool is a prime requirement for enhancing the process viability. The current work presents a novel technique of cooling only the twist drill between drilling of holes with no effect of the applied cryogenic coolant transferred to the work material. The technique is applied in the drilling of two commonly used high-strength lightweight materials: carbon fibers reinforced polymer (CFRP) and an alloy of titanium (Ti-6Al-4V). The efficacy of the cooling approach is compared with those of conventionally applied continuous cryogenic cooling and no-cooling. The effectiveness is quantified in terms of tool wear, thrust force, hole quality, specific cutting energy, productivity, and consumption of the cryogenic fluid. The experimental work leads to a finding that between-the-holes cryogenic cooling possesses a rich potential in curbing tool wear, reducing thrust force and specific energy consumption, and improving hole quality in drilling of CFRP. Regarding the titanium alloy, it yields a much better surface finish and lesser consumption of specific cutting energy.

The tool-wear characteristics of flexible printed circuit board micro-drilling and its influence on micro-hole quality

Circuit World ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 162-169 ◽  
Author(s):  
Lijuan Zheng ◽  
Chengyong Wang ◽  
Xin Zhang ◽  
Xin Huang ◽  
Yuexian Song ◽  
...  
Keyword(s):  
Tool Wear ◽  
Circuit Board ◽  
Hole Quality ◽  
Content Type ◽  
Wear Characteristics ◽  
Printed Circuit ◽  
Micro Holes ◽  
Micro Drilling ◽  
Micro Hole

Purpose Micro-holes are drilled and plated in flexible printed circuit boards (FPCs) for connecting circuits from different layers. More holes, with diameters smaller than 0.3 mm, are required to be drilled in smaller areas with flexible circuits’ miniaturization. The micro-hole quality of micro-drilling is one of the biggest issues of the flexible circuit manufacturers’ production. However, it is not easy to control the quality of micro-holes. The purpose of this study was to conduct research on the tool wear characteristics of FPC drilling process and its influence on micro-hole quality to improve the micro-hole quality of FPC. Design/methodology/approach The tool-wear characteristics of micro-drills after FPC drilling were observed. The influence of spindle speed, feed rate, number of drilled holes and entry board materials on tool-wear was analyzed. The hole qualities of FPC micro-drilling were measured and observed. The relationship between tool-wear and hole quality was analyzed. Findings The result showed that the tool-wear characteristics of FPC micro-drilling was similar to the tool-wear characteristics of rigid printed circuit board (RPC) micro-drilling. Abrasive wear occurred on both the main cutting edges and the chisel edges of micro-drills, even though there was no glass fiber reinforcing the cloth inside FPC. Resin adhesion was observed on the chisel edge. The influence of feed and number of drilled holes on tool-wear was significant. Tool-wear significantly influences the hole quality of FPC. Tool-wear will largely decrease the hole position accuracy of FPC micro-holes. Tool-wear will increase the thickness of PI nail heads and the height of exit burrs. Fracture was the main difference between tool wear of FPC and RPC micro-drilling. Resin adhesion of RPC was much more severe than FPC micro-drilling. Increasing the spindle speed properly may improve tool life and hole quality. Originality/value The technology and manufacturing of FPC has been little investigated. Research on micro-drilling FPC and research data is lacking so far. The micro-hole quality directly affects the reliability of FPC. Thus, improving the micro-hole quality of FPC is very important.

Research on Hole-Making Tools for CFRP

2013 ◽  
Vol 797 ◽  
pp. 592-596 ◽  
Author(s):  
Hong Zhou Zhang ◽  
Ying Ying Wei ◽  
Yi Chu Yuan ◽  
Hong Yu Jiang
Keyword(s):  
Selection Method ◽  
Drilling Process ◽  
Machining Parameters ◽  
Hole Quality ◽  
Technical Parameters ◽  
Machining Quality ◽  
Drilling Tools ◽  
Hole Making ◽  
Hole Machining

There are lots of defects in the drilling process of CFRP, such as splitting, etc, which may affect the assembly quality of the composite materials. Through the analysis of the drilling mechanism of CFRP, and with the help of the correlation experiments of drilling tools, the effects of machining parameters and machining tools on hole quality are studied, the optimal selection method of the drilling tools for CFRP and the selection principle of technical parameters under different machining conditions are also discussed. And the tools geometry affects the hole-machining quality of CFRP materials directly, which should be chosen in accordance with the hole-machining method.

Comparative Study of Material Damage and Tool Wear Mechanisms During Drilling of CFRP/Ti Stack

2019 ◽  
Author(s):  
Vijayathithan Mathiyazhagan ◽  
Anil Meena
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Burr Formation ◽  
Mechanical And Thermal Properties ◽  
Hole Quality ◽  
Structural Functions ◽  
Tool Wear Mechanisms ◽  
Rapid Tool

Abstract The usage of CFRP and Ti stacks in the aerospace industry has widely increased due to its mechanical properties and improved structural functions but at the same time, different mechanical and thermal properties of the CFRP and Ti makes the process difficult. Major apprehensions in the drilling of CFRP/Ti stacks include rapid tool wear and poor hole quality. Typically, the surface quality of the holes in the drilling of CFRP/Ti stack is poor due to delamination, the progression of hole diameter in CFRP and burr formation in Ti. Moreover, the flank wear on the tool also influences the surface quality of the hole produced. Therefore, the present study is mainly focused on the influence of cutting parameters on cutting forces, hole quality and tool wear characteristics. Drilling was performed on CFRP/Ti stack using coated and uncoated carbide tools. The obtained results revealed a significant correlation between tool wear and delamination characteristics.

scholarly journals Comparative Study on Cutting Performance of Conventional and Ultrasonic-assisted Bi-directional Helical Milling of CFRP

2021 ◽  
Author(s):  
Tao Chen ◽  
Yongsheng Wang ◽  
Yujiang Lu ◽  
Gang Liu ◽  
Guangjun Liu
Keyword(s):  
Tool Wear ◽  
Wear Mechanism ◽  
Shear Fracture ◽  
Cutting Edge ◽  
Helical Milling ◽  
Hole Wall ◽  
Reinforced Plastic ◽  
Ultrasonic Assisted ◽  
Hole Making

Abstract Compared with the conventional drilling, the helical milling has obvious advantages in making holes of Carbon Fiber Reinforced Plastic (CFRP). Nevertheless, the rapid wear of cutting edges readily causes some defects in the outlet holes, such as burrs and tearing. In order to improve the hole-making quality of CFRP, a comparative experimental study on conventional and ultrasonic-assisted bidirectional helical milling of CFRP was carried out. The wear mechanism of the forward and reverse cutting edges was analyzed in the two types of machining, and the change laws of cutting forces and hole wall quality were obtained by different machining means. The experimental results indicated that the flank face of forward and reverse cutting edges was dominated by the abrasive wear mechanism in the ultrasonic-assisted milling. With aggravation of the tool wear, no obvious coating peeled off the forward cutting edge, the reverse cutting edge remained relatively intact, and the wear form of neither cutting edge changed. Furthermore, in the ultrasonic-assisted reverse milling, the axial force and hole diameter deviation were restrained better than in the conventional milling, and especially when the tool wear occurred, the cutting force fluctuation varied slowly. In the ultrasonic-assisted milling, the shear fracture predominated over bending fracture. Meanwhile, the time variation of effective rake angles improved the chip breaking and removing performance of cutters, and thus the machining quality of hole wall was enhanced obviously.

Comparative Study on Helical Milling and Drilling of Ti-6Al-4V

2012 ◽  
Vol 499 ◽  
pp. 200-204 ◽  
Author(s):  
Xu Da Qin ◽  
Xiao Tai Sun ◽  
Q. Wang ◽  
S.M. Chen ◽  
H. Li
Keyword(s):  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Tools ◽  
Axial Direction ◽  
Helical Milling ◽  
End Mill ◽  
Hole Quality ◽  
Hole Making ◽  
Series Of Experiments ◽  
Better Than

Helical milling is a hole making process by milling in which the center of end mill orbits around the center of the hole while spinning on its axis and feeding in the axial direction. This paper makes a comparison between drilling and helical milling in cutting forces, hole quality and tool wear through a series of experiments. The results show that the axial cutting force of helical milling is far less than that of drilling and the holes quality is also better than traditional drilling. Cutting tools show excellent machinability in helical milling.

scholarly journals Analyzing the Effects of the Kinematic System on the Quality of Holes Drilled in 42CrMo4 + QT Steel

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4046
Author(s):  
Mateusz Bronis ◽  
Edward Miko ◽  
Lukasz Nowakowski
Keyword(s):  
Cutting Speed ◽  
Hole Drilling ◽  
Internal Cooling ◽  
Hole Quality ◽  
The Third ◽  
Kinematic System ◽  
Turning Center ◽  
Dimensional Errors ◽  
The Relationship

This article discusses the relationship between the kinematic system used in drilling and the quality of through-holes. The drilling was done on a CTX Alpha 500 universal turning center using a TiAlN-coated 6.0 mm drill bit with internal cooling, mounted in a driven tool holder. The holes were cut in cylindrical 42CrMo4 + QT steel samples measuring 30 mm in diameter and 30 mm in length. Three types of hole-drilling kinematic systems were considered. The first consisted of a fixed workpiece and a tool performing rotary (primary) and linear motions. In the second system, the workpiece rotated (primary motion) while the tool moved linearly. In the third system, the workpiece and the tool rotated in opposite directions; the tool also moved linearly. The analysis was carried out for four output parameters characterizing the hole quality (i.e., cylindricity, straightness, roundness, and diameter errors). The experiment was designed using the Taguchi approach (orthogonal array). ANOVA multi-factor statistical analysis was used to determine the influence of the input parameters (cutting speed, feed per revolution and type of kinematic system) on the geometrical and dimensional errors of the hole. From the analysis, it is evident that the kinematic system had a significant effect on the hole roundness error.

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