Performance and mechanism of hole-making of CFRP/Ti-6Al-4V stacks using ultrasonic vibration helical milling process

Author(s):  
Yuhe Zou ◽  
Guang Chen ◽  
Chengzu Ren ◽  
Jiaying Ge ◽  
Xuda Qin
2013 ◽  
Vol 465-466 ◽  
pp. 1075-1079 ◽  
Author(s):  
Erween Abdul Rahim ◽  
Z. Mohid ◽  
M.R. Hamzah ◽  
A.F. Yusuf ◽  
N.A. Rahman

Hole making process is not strictly to the drilling technique where others machining could also influence to the quality in CFRP hole.Therefore, helical milling process becomes as an alternative method to produces bore on CFRP plate thus minimizing the defects. The common defects on CFRP are delamination, splintering and cracking. Meanwhile, if the CFRP stacking together with aluminum plate, burr at exit hole of aluminium plate is produced. Therefore, it is essential to control the critical machining parameters to assure a good quality of the hole. The main objective of this project is to improve the hole quality of CFRP/AL stack in terms of surface roughness using helical milling technique. In addition the cutting force and temperature will be measured as well. There are three levels of cutting speeds; two levels of feed rate and depth per helical path are made accordingly to helical milling characteristics. It was found that all tool design exhibit comparable performance for helical milling process on CFRP/Al stack.


Author(s):  
Omid Paysarvi ◽  
Mohammad Mahdi Abootorabi ◽  
Mohammad Mahdi Jalili

Helical milling is one of the novel hole-making methods to create a hole with high accuracy and quality. In this study, the helical milling process is dynamically modeled using a set of second-order differential equations. In this modeling, the tool is considered a cantilever beam with a degree of freedom in all three directions of x, y, and z. Experimental tests were conducted to investigate the validity of the obtained theoretical relations and the effects of different parameters such as material, diameter, and rotational speed of the cutting tool on the precision of the created hole. The error of the theoretical relations in predicting the hole diameter is 2.7%, indicating the high precision of the accomplished modeling. Theoretical relations show that the error of the chip removal path decreases by increasing each of the parameters, namely, tool stiffness, the rotational speed of the tool, tool diameter, and tangential feed per tooth. In contrast, the error of the chip removal path increases by increasing each of the parameters, namely, the speed of the tool in the helical path and axial feed per tooth. It has been shown that improving the cutting tool material in terms of strength or increasing the rotational speed of the tool and the cutting tool diameter causes a reduction in the diametrical error. It has been shown that the diametrical error rate is 0.9% with the change of the cutting tool from HSS-E to carbide, and it has reduced to 0.6% by increasing the rotational speed of the tool from 900 r/min to 2100 r/min.


2012 ◽  
Vol 576 ◽  
pp. 68-71 ◽  
Author(s):  
Erween Abdul Rahim ◽  
Zazuli Mohid ◽  
M.F.M. Jamil ◽  
K.C. Mat ◽  
R. Koyasu ◽  
...  

Generate borehole by helical milling process may be used effectively since accurate location of the hole may be secured by means of the feed screw graduations. Fiber delamination which is the main defect occurred during hole making process on carbon fiber reinforced polymer (CFRP) were investigate throughout an experimental study. Effects of thrust force (Fz), delamination factor (Fd) and surface roughness are evaluated. Objective of the experiment are to find best cutting parameter and tool design suitable to performed helical milling operation on CFRP. Two types of end mill with 4 flutes were used and results are evaluated. It was found that tool design 2-1 has higher performance on CFRP.


Author(s):  
Jue Wang ◽  
Derek Yip-Hoi

Helical milling is a 3-axis machining operation where a cutting tool is feed along a helix. This operation is used in ramp-in and ramp-out moves when the cutting tool first engages the workpiece, for contouring and for hole machining. It is increasingly finding application as a means for roughing large amounts of material during high speed machining. Simulating the helical milling process requires Cutter/Workpiece Engagement (CWE) geometry in order to predict cutting forces. The calculation of these engagements is challenging due to the complicated and changing intersection geometry that occurs between the cutter and the in-process workpiece. For hole milling an additional complication comes from self-intersections that occur with the tool swept volume. This makes the generation of the instantaneous in-process workpiece needed for finding the CWE difficult. In this paper we present an analytical approach for finding the engagement geometry that utilizes the intersection curves between a cylinder representing a flat end mill and the helicoidal surface generated by the bottom of the tool as it feeds downwards along the helix. This technique can be integrated into a solid modeler based approach for machining simulation. It has the advantage of not require instantaneous updates of the workpiece as is typically the case in finding CWEs.


2020 ◽  
Vol 253 ◽  
pp. 112778
Author(s):  
Guolin Yang ◽  
Zhigang Dong ◽  
Shang Gao ◽  
Yan Bao ◽  
Renke Kang ◽  
...  

Author(s):  
Eyyup Aras ◽  
Derek Yip-Hoi

Helical milling is a 3-axis machining operation where a cutting tool is feed along a helix. This operation is used in ramp-in and ramp-out moves when the cutting tool first engages the workpiece, for contouring and for hole machining. It is increasingly finding application as a means for roughing large amounts of material during high speed machining. Modeling the helical milling process requires cutter/workpiece engagements (CWEs) geometry in order to predict cutting forces. The calculation of these engagements is challenging due to the complicated and changing intersection geometry that occurs between the cutter and the in-process workpiece. In this paper we present a geometric modeling methodology for finding engagements during helical milling with flat end mills. A mapping technique has been developed that transforms a polyhedral model of the removal volume from Euclidean space to a parametric space defined by location along the tool path, engagement angle and the depth-of-cut. As a result, intersection operations are reduced to first order plane-plane intersections. This approach reduces the complexity of the cutter/workpiece intersections and also eliminates robustness problems found in standard polyhedral modeling and improves accuracy over the Z-buffer technique. The reported method has been implemented and tested using a combination of commercial applications. This paper highlights ongoing collaborative research into developing a Virtual Machining System.


2014 ◽  
Vol 1061-1062 ◽  
pp. 497-506 ◽  
Author(s):  
Qing Liang Chen ◽  
Xue Mei Chen ◽  
Zuo Heng Duan ◽  
Wen Yuan Cun

Compared with conventional push drilling, helical milling (orbital drilling) shows great advantages in aeronautical hard-machining materials hole making. However, helical milling of titanium alloy and carbon fiber reinforced plastic (CFRP) under dry cut condition still faces challenges such as burr of titanium alloy hole exit and CFRP hole delamination. In order to solve these problems, an innovative helical milling tool with distributed multi-point front cutting edge is designed based on the chip-splitting mechanism and tool movement feature. The description of cutting edge movement track and simulation of chip shape is used to analyze different functions of front and peripheral cutting edges, the chip-splitting result and the specialized tool's service life. The helical milling experiments are aimed to test the performance of the specialized tool compared with that of traditional end mill. Results show that the specialized tool can machine titanium hole free of burr and CFRP hole without delamination under dry cut condition. The specialized tool has a longer service life with its machining capacity amounting to 80 titanium holes and 65 CFRP holes..


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