Effect of cutting speed on surface integrity and chip formation in micro-cutting of Zr-based bulk metallic glass

2021 ◽  
Author(s):  
Sau Yee Chau ◽  
Suet To ◽  
Hao Wang ◽  
Wai Sze Yip ◽  
Kang Cheung Chan ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Surface Integrity ◽  
Chip Formation ◽  
Cutting Speed ◽  
Micro Cutting

Machinability of BMG

2012 ◽  
Vol 521 ◽  
pp. 225-253
Author(s):  
Mustafa Bakkal
Keyword(s):  
High Temperature ◽  
Metallic Glass ◽  
Viscous Flow ◽  
Bulk Metallic Glass ◽  
Light Emission ◽  
Cutting Speed ◽  
Good Surface ◽  
High Cutting Speed ◽  
Exothermic Chemical Reaction ◽  
Good Surface Roughness

This chapter covers the series of machinability evaluation test result and discussions of Zr52.5Ti5Cu17.9Ni14.6Al10bulk metallic glass (BMG). These tests are lathe turning, drilling, milling and preliminary level grinding tests. In the continuous machining methods such as turning, drilling and grinding of BMG, above a threshold cutting speed, the low thermal conductivity of BMG leads to chip temperatures high enough to cause the chip oxidation and associated light emission. The high temperature produced by this exothermic chemical reaction causes crystallization within the chips. Chips morphology suggests that increasing amounts of viscous flow control the chip-removal process. Moreover, viscous flow and crystallization can occur during the machining of the bulk metallic glass, even under the high temperature gradient and strain rate. High cutting speed significantly reduced the forces for BMG machining due to thermal softening. However, in intermittent cutting process which is milling, there is no high temperature problem, special burr formations the rollover and the top burr were observed along the slot and achieved good surface roughness, Ra= 0.113 μm, using conventional WC-Co cutting tool. In each method, tests repeated for the conventional materials for comparison purpose. This study concludes the precision machining of BMG is possible with the selection of feasible tools and process parameters for each method.

scholarly journals Investigation of Chip Formation and Surface Integrity when Micro-cutting cp-Titanium with Ultra-fine Grain Cemented Carbide

Procedia CIRP ◽  
2016 ◽  
Vol 45 ◽  
pp. 115-118 ◽  
Author(s):  
F. Schneider ◽  
R. Bischof ◽  
B. Kirsch ◽  
C. Kuhn ◽  
R. Müller ◽  
...  
Keyword(s):  
Surface Integrity ◽  
Chip Formation ◽  
Cemented Carbide ◽  
Micro Cutting ◽  
Fine Grain

Microscale Drilling of Bulk Metallic Glass

2013 ◽  
Vol 1 (4) ◽  
Author(s):  
James Zhu ◽  
Hyun Jin Kim ◽  
Shiv G. Kapoor
Keyword(s):  
Metallic Glass ◽  
Tool Wear ◽  
Bulk Metallic Glass ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Acoustic Emissions ◽  
Chip Morphology ◽  
High Rate ◽  
Burr Height ◽  
Drilling Performance

The microscale drilling performance of a Zr-based bulk metallic glass (BMG) is investigated in this paper. Crystallization, drill temperature, axial force, spindle load (SL), acoustic emissions (AE), chip morphology, hole diameter, and entry burr height are measured and analyzed with varying cutting speed and chip load. The progression of tool wear is assessed using stereo-microscopy techniques. At small chip loads, minimum chip thickness (MCT) is observed to shift cutting mechanics from a shear-dominated to a ploughing-dominated regime. Consequently, evidence of drill instability and larger burr height are observed. As drilling temperatures rise above the glass transition temperature, the BMG thermally softens due to the transition to a super-cooled liquid state and begins to exhibit viscous characteristics. In the tool wear study using tungsten carbide microdrills, rake wear is found to dominate compared to flank wear. This is attributed to a combination of a high rate of diffusion wear on the rake face as well as lower abrasion on the flank due to the decreased hardness from thermal softening-induced viscous flow of BMG.

scholarly journals Investigation on chip formation and surface morphology in orthogonal machining of Zr-based bulk metallic glass

2019 ◽  
Vol 19 ◽  
pp. 25-28 ◽  
Author(s):  
Karuna Dhale ◽  
Nilanjan Banerjee ◽  
Ramesh Kumar Singh ◽  
José C. Outeiro
Keyword(s):  
Metallic Glass ◽  
Surface Morphology ◽  
Bulk Metallic Glass ◽  
Chip Formation ◽  
Orthogonal Machining ◽  
On Chip

scholarly journals High performance cutting of Zr-based bulk metallic glass: a review of chip formation

Procedia CIRP ◽  
2018 ◽  
Vol 77 ◽  
pp. 421-424 ◽  
Author(s):  
Feng Ding ◽  
Chengyong Wang ◽  
Tao Zhang ◽  
Lijuan Zheng ◽  
Xuguang Zhu
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Chip Formation ◽  
High Performance

Chip Formation during Precision Cutting of Metallic Glass

2016 ◽  
Vol 1136 ◽  
pp. 265-270
Author(s):  
Hiroyuki Kodama ◽  
Koichi Okuda ◽  
Tsukasa Inada
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glass ◽  
Chip Formation ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Shear Angle ◽  
Chip Formation Mechanism

The chip formation mechanism during precision cutting of metallic glass (Zr55Cu30Ni5Al10 at%) was investigated around the glass transition temperature (673 K). Orthogonal cutting of metallic glass are conducted on a fly-cutting machine at various cutting speeds. The new surface of the chips was slightly shiny while the free surface exhibited lamellar slip structure. The cutting temperature was a proportional to the cutting ratio and chip shear angle. The surface integrity worsened with an increased flow of cutting chip due to an increase in the cutting speed. An increase in the cutting temperature caused the chips formation to change from flow type chips to discontinuous chips. When the cutting speed exceeded 300 m/min, the shear angle increased while the shear pitch of the chips decreased. It appears that when the cutting temperature exceeded the glass transition temperature, the strength of the metallic glass decreased and the ductility mode changed due to viscous flow.

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