Effect of cutting edge radius on micro end milling: force analysis, surface roughness, and chip formation

2018 ◽  
Vol 97 (1-4) ◽  
pp. 711-722 ◽  
Author(s):  
K. Vipindas ◽  
K. N. Anand ◽  
Jose Mathew
2019 ◽  
Vol 3 (1) ◽  
pp. 25 ◽  
Author(s):  
Jue-Hyun Lee ◽  
Angela Sodemann

In this paper, the reliability of a new online cutting edge radius estimator for micro end milling is evaluated. This estimator predicts the cutting edge radius by detecting the drop in the chip production rate as the cutting edge of a micro end mill slips over the workpiece when the minimum chip thickness (MCT) becomes larger than the uncut chip thickness (UCT), thus transitioning from the shearing to the ploughing dominant regime. This study proposes a method of calibrating the cutting edge radius estimator by determining two parameters from training data: a ‘size filtering threshold’ that specifies the smallest-size chip that should be counted, and a ‘drop detection threshold’ that distinguishes the drop in the number of chips at the actual critical feedrate from the number drops at the other feedrates. This study then evaluates the accuracy of the calibrated estimator from testing data for determining the ‘critical feedrate’—the feedrate at which the MCT and UCT will be equal. It is found that the estimator is successful in determining the critical feedrate to within 1 mm/s in 84% of trials.


Author(s):  
Yang Li ◽  
Xiang Cheng ◽  
Siying Ling ◽  
Guangming Zheng ◽  
Huanbao Liu ◽  
...  

Previous studies found that the peripheral cutting edge and end cutting edge in micro end milling had different cutting phenomena considering the size effect in micro cutting processes. This paper is a further study on this point considering different workpiece materials and cutting edge radii. Finite element simulations have been conducted to determine the minimum undeformed chip thickness (MUCT) by the chip morphology and the results are verified by micromilling experiments. Both the simulations and experiments show that the MUCT of the peripheral cutting edge and the end cutting edge are different even if the cutting edge radii remain unchanged. The MUCT is directly proportional to the cutting edge radius. Material properties also have some effects on the MUCT of the peripheral cutting edge. But it has limited effects on that of the end cutting edge. The results indicate that the feed engagement other than the axial depth of cut should be carefully selected in micro end milling when considering different workpiece materials.


2014 ◽  
Vol 651-653 ◽  
pp. 764-767
Author(s):  
Tao Zhang ◽  
Hou Jun Qi ◽  
Gen Li

Micro cutting is a promising manufacturing method to obtain good surface integrity. Surface roughness shows size effect when the uncut chip thickness is smaller than the cutting edge radius. A special micro slot on the flank face of cutting tools was manufactured with discharge. Two groups of micro orthogonal cutting were conducted. The surface roughness of machined surface was measured and compared to each other. The results show that surface roughness decreases first and then increases with the ratio of uncut chip thickness to cutting edge radius. The surface machined with micro slot is better than that of without micro slot due to the micro slot restrain the back side flow of work piece based on the finite element model.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3078
Author(s):  
Pavel Filippov ◽  
Michael Kaufeld ◽  
Martin Ebner ◽  
Ursula Koch

Micro-milling is a promising technology for micro-manufacturing of high-tech components. A deep understanding of the micro-milling process is necessary since a simple downscaling from conventional milling is impossible. In this study, the effect of the mill geometry and feed per tooth on roughness and indentation hardness of micro-machined AA6082 surfaces is analyzed. A solid carbide (SC) single-tooth end-mill (cutting edge radius 670 nm) is compared to a monocrystalline diamond (MD) end-mill (cutting edge radius 17 nm). Feed per tooth was varied by 3 μm, 8 μm and 14 μm. The machined surface roughness was analyzed microscopically, while surface strain-hardening was determined using an indentation procedure with multiple partial unload cycles. No significant feed per tooth influence on surface roughness or mechanical properties was observed within the chosen range. Tools’ cutting edge roughness is demonstrated to be the main factor influencing the surface roughness. The SC-tool machined surfaces had an average Rq = 119 nm, while the MD-tool machined surfaces reached Rq = 26 nm. Surface strain-hardening is influenced mainly by the cutting edge radius (size-effect). For surfaces produced with the SC-tool, depth of the strain-hardened zone is higher than 200 nm and the hardness increases up to 160% compared to bulk. MD-tool produced a thinner strain-hardened zone of max. 60 nm while the hardness increased up to 125% at the surface. These findings are especially important for the high-precision manufacturing of measurement technology modules for the terahertz range.


2018 ◽  
Vol 7 (4.30) ◽  
pp. 53
Author(s):  
Husni Nazra Abu Bakar ◽  
Jaharah A. Ghani ◽  
Che Hassan Che Haron

Rounded cutting-edge radius is commonly applied to finish and semi-finish cutting, precision machining and micro-machining. The optimum effect is closely related to the work and tool material as well as machining parameters. However, for numerous cutting process, the optimal radius of rounded cutting-edge radius and machining parameters applied in the AISI H13 of end-milling is yet unknown Therefore, in improving tool life and cutting tool performance, a suitable design of cutting edge geometry regarding cutting edge-radius and machining parameters need to be examined and properly selected. In this regard, the paper deals to examine the effect of cutting edge-radius in rounded form and machining parameters of cutting force, cutting temperature and chip formation through the end-milling process of AISI H13 using uncoated cemented carbide cutting tool through finite element simulation of Thirdwave AdvantEdge 7.2 software. The machining parameters applied in the simulation setup were 200 and 240m/min of cutting speed, 0.03 and 0.06mm/tooth of feed-rate and axial depth of cut of 0.1 and 0.2mm while width of cut in radial direction was kept constant at 6.0mm. The cutting geometries includes the cutting-edge radius of 0.03 and 0.05mm and 10° of rake angle. The obtained results revealed that cutting forces and cutting temperature is increase as depth of cut in axial direction and cutting-edge radius increases while increasing value of speed and feed-rate of cutting resulted in decreasing cutting forces but increasing cutting temperature. The maximum cutting temperature is 674.91℃. The value obtained is lesser than the AISI H13 austenitizing temperature, therefore a layer known as white layer is supposedly hard to be created based on the cutting geometry and machining parameters applied.  


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