Burr and Cap Formation by Orbital Drilling of Aluminum

2009 ◽  
pp. 31-45 ◽  
Author(s):  
E. Brinksmeier ◽  
S. Fangmann
Keyword(s):  
Orbital Drilling

Machinability Evaluation of Inclined Planetary Motion Milling System for Difficult-to-Cut Materials

2015 ◽  
Vol 656-657 ◽  
pp. 320-327 ◽  
Author(s):  
Hidetake Tanaka ◽  
Toma Yoshita
Keyword(s):  
Cutting Tool ◽  
Rotation Axis ◽  
Tool Geometry ◽  
Planetary Motion ◽  
Orbital Drilling ◽  
Drilling Technique ◽  
Cutting Model ◽  
Cutting Experiments ◽  
Tool Rotation ◽  
The Revolution

CFRP and Titanium alloy, which are known as difficult-to-cut materials have been widely used as structural material in aviation industries. The orbital drilling is one of an effective drilling technique for the industries. However this technique has some disadvantages such as increase of cutting force due to cutting with tool center point, inertial vibration generated by revolution and high installation cost. In order to improve the disadvantages, we have invented a new drilling technique which is called inclined planetary motion milling. The inclined planetary motion milling and the planetary mechanism drilling has two axes of cutting tool rotation axis and revolution axis. Cutting tool rotation axis of the orbital drilling is moved parallel to the revolution axis in eccentric. On the other hand, in the case of the inclined planetary motion milling, eccentric of the cutting tool rotation axis is realized by inclination of a few degrees from the revolution axis. Therefore, the movement of eccentric mechanism can be reduced by comparison with the orbital drilling because inclined angle is smaller than eccentricity of the cutting tool tip. As a result, eccentric mechanism can be downsized and inertial vibration is reduced. In the study, a geometrical cutting model of inclined planetary motion milling was set up. The theoretical surface roughness of the inside of drilled holes by use of two types cutting tool geometry were calculated based on the model. And cutting experiments using the new prototype for CFRP were carried out in order to evaluate the effect on machinability with change of cutting point atmosphere. In addition, optimal cutting condition was derived according to cutting experiments for titanium alloys utilizing the orthogonal array.

scholarly journals A Force Sensorless Method for CFRP/Ti Stack Interface Detection during Robotic Orbital Drilling Operations

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Qiang Fang ◽  
Ze-Min Pan ◽  
Bing Han ◽  
Shao-Hua Fei ◽  
Guan-Hua Xu ◽  
...  
Keyword(s):  
Cutting Force ◽  
Thrust Force ◽  
Cutting Parameters ◽  
Force Model ◽  
Drilling Process ◽  
Reinforced Plastics ◽  
Orbital Drilling ◽  
Drilling Parameters ◽  
Drilling Operations ◽  
Machining Properties

Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti) stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm) before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation.

Experimental Characterization and Multi-Objective Optimization of the Orbital Drilling Process of CFRP

2013 ◽  
Author(s):  
A. Sadek ◽  
A. O. Nassef ◽  
M. Meshreki ◽  
M. H. Attia
Keyword(s):  
Cutting Forces ◽  
Research Work ◽  
Axial Direction ◽  
Fiber Reinforced Polymers ◽  
Test Material ◽  
Drilling Process ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Orbital Drilling ◽  
Work Done

Defects associated with drilling of Carbon Fiber-Reinforced Polymers (CFRPs) are of major economic and safety concerns for aerospace manufacturers. One of the most critical defects associated with drilling of CFRP laminates is delamination of layers which can be avoided by keeping the drilling forces below some threshold levels. Orbital Drilling (OD) is an emerging drilling process that exhibits lower cutting forces and temperatures, easier chip removal, higher produced surface quality, longer tool life, and a high possibility for dry machining. The OD process is featured by cyclic engagement and disengagement between the tool and the workpiece whereby a considerable part of the work done by the tool is directed towards the tangential direction while the work done in the axial direction is reduced. This reduces the risk of delamination at the exit. The objective of this research work is to investigate the effect of the OD process key parameters with respect to the produced hole attributes (surface roughness, delamination, and hole accuracy), as well as the cutting forces and temperatures. All the OD tests were performed under dry conditions using a four-flute 6.35 mm end-mill. The cutting forces were recorded using a 3-component dynamometer Kistler 9255B and cutting temperatures were measured using a FLIR ThermoVision A20M Infrared camera at the holes exit. A full factorial design of the experiment was used whereby the feeds varied from 60 to 360 mm/min and the speeds from 6,000 to 16,000 rpm. The test material used was a quasi-isotropic laminate comprising woven graphite epoxy prepreg. Analysis of the results showed 45% reduction in the axial force component in orbital drilling (OD), compared to conventional drilling. None of the holes produced by the entire set of experiments has experienced any entry or exit delamination. ANOVA was used to identify the significance of the controllable variables on the experimental outputs. To overcome the challenge of optimizing the competing parameters of the hole quality attributes while maximizing the productivity, an algorithm was applied by hybridizing Kriging as a meta-modeling technique with evolutionary multi-objective optimization to optimize the cutting parameters.

Experimental Study on Orbital Drilling Force and Machining Quality of CFRP

2014 ◽  
Vol 1061-1062 ◽  
pp. 542-549
Author(s):  
Xue Mei Chen ◽  
Qing Liang Chen ◽  
Feng Tao He ◽  
Xi Feng Fan
Keyword(s):  
Thrust Force ◽  
Orthogonal Experiment ◽  
Cutting Parameters ◽  
Force Model ◽  
Drilling Process ◽  
Drilling Force ◽  
Drilling Tool ◽  
Orbital Drilling ◽  
Reinforced Plastic ◽  
Predominant Factor

This paper aims to investigate orbital drilling process in carbon-fiber reinforced plastic (CFRP) composites with multi-point orbital drilling tool based on the robot automatic drilling system. One orthogonal experiment has been carried out, and the cutting forces of different parameters were measured online by dynamometer. Furthermore, the cutting force model was established through regression analysis, and the impacts of cutting parameters on thrust force were deeply analyzed. In addition, delamination and tear defects were inspected respectively, and the relationship between thrust force and delamination and tear was discussed. Our results indicate that thrust force increased with the increasing feed rate and axial feed depth, while decreased with the increasing spindle speed. Axial feed depth was found as the predominant factor on thrust force and defects. At last, the cutting parameters was optimized and then thrust force decreased more than 26% with almost none tear and burr around the hole, which indicates a better machine quality.

scholarly journals Experimental Investigation On Machining Performance During Orbital Drilling of CFRP

2021 ◽  
Author(s):  
Linghao Kong ◽  
Dong Gao ◽  
Yong Lu ◽  
Pengfei Zhang
Keyword(s):  
Tool Wear ◽  
Thrust Force ◽  
Cutting Temperature ◽  
Cutting Parameters ◽  
Machining Performance ◽  
Machining Quality ◽  
Orbital Drilling ◽  
Orthogonal Experiments ◽  
Hole Making ◽  
Tool Diameter

Abstract As the most promising CFRP hole making method, orbital drilling is widely concerned. This paper aims to understand the influence of the cutting parameters, tool diameters and ratio between milling and drilling (Rm&d) on thrust force, cutting temperature, tool wear and machining quality in CFRP orbital drilling. The effects of cutting parameters on thrust force and cutting temperature were studied by orthogonal experiments, and experiments were performed to investigate the variations of tool diameters, ratio between drilling and milling on thrust force, cutting temperature, tool wear and machining quality. The experimental results show that the tangential feed rate has no apparent effects on thrust force, but it appreciably impacts on the cutting temperature. The selection of tool diameter and the Rm&d has specific influence on tool wear, machining quality and cutting temperature. The result is helpful for selecting cutting parameters and tool diameters for high quality holes machining in CFRP orbital drilling.

3D Finite Element Assisted Numerical Simulation of Orbital Drilling Process of Ti6Al4V

2019 ◽  
Author(s):  
Salman Pervaiz ◽  
Ali Daneji ◽  
Sathish Kannan
Keyword(s):  
Finite Element ◽  
Rotational Speed ◽  
Cutting Forces ◽  
Threshold Value ◽  
Machining Process ◽  
Burr Formation ◽  
Drilling Process ◽  
Low Thrust ◽  
High Rotational Speed ◽  
Orbital Drilling

Abstract Drilling is one of most executed manufacturing operations to assist the assembling of different engineering components. In orbital drilling process, a milling tool is rotating along its own axis in combination with the spiral rotational movement. The rotation of tool about its own axis is with high rotational speed, but the spiral movement of tool is at low rotational speed. These rotational movements generate a hollow geometry when moved in combination. Orbital drilling process is emerging as a viable drilling process when burr formation has to be reduced from the metallic workpiece. It is gaining more popularity in the aerospace industry due to its ability to machine holes in difficult to cut alloys, composites and composite stacks. Major advantages of orbital drilling are linked with efficient chip evacuation, reduction in heat build-up and low thrust forces due to its intermittent cutting nature. The cutting forces generated during the process can be taken as a significant output parameter that play a vital role towards the overall performance of the cutting process. Controlling the cutting forces under threshold value can improve the overall machining efficiency by limiting associated deflections, tool wear and energy consumption. The current paper aims to study the orbital drilling process using finite element (FE) assisted numerical methodology. The study will utilize different orbital drilling parameters such as spindle speed, orbit speed and axial feed rate, and explore their influence on the over all machining process.

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