Self-Sharpening Failure Characteristic of a Si3N4 Ceramic Tool in High Speed Cutting of Inconel 718

2016 ◽  
Vol 693 ◽  
pp. 1135-1142 ◽  
Author(s):  
Guang Ming Zheng ◽  
Jun Zhao ◽  
Xiang Cheng ◽  
Min Wang
Keyword(s):  
Inconel 718 ◽  
High Speed ◽  
Adhesive Wear ◽  
Failure Mechanisms ◽  
Cutting Edge ◽  
Ceramic Tool ◽  
Tool Failure ◽  
High Speed Cutting ◽  
Failure Characteristic ◽  
Failure Evolution

A Si3N4 ceramic tool material with high mechanical properties was fabricated by hot-pressing sintering process. The high speed machining of Inconel 718 tests were carried out with round ceramic inserts. The failure surface and microstructure were analyzed by scanning electron microscopy (SEM) to reveal the ceramic tool failure mechanisms. The results showed that the main failure mechanisms of the Si3N4 ceramic tool were flaking, micro-chipping, abrasive wear and adhesive wear in the turning process. On the other hand, chipping, flaking and adhesive wear were the main failure reasons in the milling process. Meanwhile, some small flaking along the cutting edge and step-shaped flaking on the rake face closed to the cutting edge were found on the failure surfaces, which was a typical self-sharpening failure characteristic of the ceramic tool in the high-speed cutting process. This tool failure evolution characteristic of the ceramic tool can be attributed to its higher flexural strength and fracture toughness, which was beneficial to improve the tool life and was constrained by cutting conditions.

Progressive Tool Failure in High Speed End Milling of Inconel 718 with Coated Carbide Inserts

2011 ◽  
Vol 188 ◽  
pp. 32-37 ◽  
Author(s):  
An Hai Li ◽  
Jun Zhao ◽  
Z.Q. Pei ◽  
S.G. Guo
Keyword(s):  
Abrasive Wear ◽  
Inconel 718 ◽  
Adhesive Wear ◽  
End Milling ◽  
Failure Mechanisms ◽  
Cutting Speed ◽  
Fatigue Wear ◽  
Edge Chipping ◽  
Tool Failure ◽  
Coated Carbide

The failure progression of coated carbide tools in end milling of Inconel 718 superalloy was investigated. Tool wear was measured and failure mechanisms were discussed in the experimental process periodically. The experimental results indicated that the tool failure mechanisms were synergistic interaction among abrasive wear, adhesive wear, and fatigue wear. However, abrasive wear and adhesive wear were the main failure mechanisms at the beginning, fatigue wear prevailed the upper hand around the time when edge chipping appeared, and after edge chipping abrasive wear and adhesive wear dominated until the failure time. In addition, the macroscopic failure of the cutting tools is closely correlated to the nucleation and propagation of the crack under cyclic mechanical and thermal impact forces. Mechanical fatigue wear was the key form of fatigue wear at lower cutting speed, while at higher cutting speed thermal fatigue wear was the dominant fatigue wear.

An Integral Method to Determine Workpiece Flow Stress and Friction Characteristics in Metal Cutting

2015 ◽  
Vol 9 (6) ◽  
pp. 775-781
Author(s):  
Norfariza Wahab ◽  
◽  
Yumi Inatsugu ◽  
Satoshi Kubota ◽  
Soo-Young Kim ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Edge ◽  
Cutting Process ◽  
Machining Parameters ◽  
Friction Characteristics ◽  
High Speed Cutting

In recent times, numerical simulation techniques have been commonly used to estimate and predict machining parameters such as cutting forces, stresses, and temperature distribution. However, it is very difficult to estimate the flow stress of a workpiece and the friction characteristics at a tool/chip interface, particularly during a high-speed cutting process. The objective of this study is to improve the accuracy of the present method and simultaneously determine the characteristics of the flow stress of a workpiece and friction at the cutting edge under a high strain rate and temperature during the cutting process. In this study, the Johnson-Cook (JC) flow stress model is used as a function of strain, strain rate, and temperature. The friction characteristic was estimated by minimizing the difference between the predicted and measured results of principal force, thrust force, and shear angle. The shear friction equation was used to estimate the friction characteristics. Therefore, by comparing the measured values of the cutting forces with the predicted results from FEM simulations, an expression for workpiece flow stress and friction characteristics at the cutting edge during a high-speed cutting process was estimated.

High-Speed Finishing of Hard Gear Teeth with cBN-Tipped Hob

2008 ◽  
Vol 2 (5) ◽  
pp. 348-353 ◽  
Author(s):  
Yoji Umezaki ◽  
◽  
Yasutsune Ariura ◽  
Toshio Suzuki ◽  
Ryohei Ishimaru ◽  
...  
Keyword(s):  
Surface Properties ◽  
High Speed ◽  
High Efficiency ◽  
Cubic Boron Nitride ◽  
Cutting Temperature ◽  
Cutting Edge ◽  
Wear Properties ◽  
High Speed Cutting ◽  
Gear Teeth ◽  
Finished Surface

The hobbing finish of hard gear teeth such as case-hardened gears is anticipated for practical use in high efficiency production. We studied wear and finished surface properties in cutting tests using a cubic boron nitride (cBN) hob cutter in high-speed cutting at 900 m/min of case-hardened steel. The cBN content in tip ingredients is related to wear, and tips high in cBN content are superior in wear resistance. The high thermal conductivity of cBN tips helps transfer cutting temperature heat to chips, melting and adhering them to the relief surface. Flaking may occur on the cutting edge but new chipping does not occur although chipping may exist after grinding. Finished surface roughness is influenced by horning on the cutting edge. Round horning leads to a smooth surface. High-speed finishing with cBN-tipped hobs is analyzed in view of cBN tip grinding and finished surface properties, in addition to wear properties.

Ceramic Tool Materials for High Speed Cutting Process

2010 ◽  
Vol 65 ◽  
pp. 56-60 ◽  
Author(s):  
Gabriela Górny ◽  
Roman Pampuch ◽  
Ludosław Stobierski ◽  
Paweł Rutkowski
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Speed ◽  
Solid Lubricant ◽  
Matrix Composites ◽  
Ceramic Tool ◽  
High Speed Cutting ◽  
Tool Materials ◽  
Material Homogeneity ◽  
Si3n4 Matrix

Frictional and mechanical properties of hot-pressed Al2O3 and Si3N4 - matrix composites containing up to 5 vol. % hexagonal BN as a solid lubricant. A very low coefficient of friction which is necessary for high-speed cutting has been observed. Fracture toughness remained constant with increase of h-BN content while flexural strength changes with the hBN content have been found to depend upon the material homogeneity. The work has been supported by EU Funds in Poland under contract UDA-POIG.01.03-12-024/08-00.and has been realized in the frame of scientific-industrial consortium.

Influence of gas blow on high-speed cutting of Inconel 718 by ceramic end mill

2018 ◽  
Vol 2018.12 (0) ◽  
pp. C15
Author(s):  
Yoshiyuki Matsui ◽  
Katsuhiko Sakai ◽  
Hiroo Shizuka ◽  
Masayuki Okada ◽  
Syusuke Suzuki ◽  
...  
Keyword(s):  
Inconel 718 ◽  
High Speed ◽  
End Mill ◽  
High Speed Cutting

Influence of Coolant Application Direction on the Cutting Performance of Ceramic Tool in High-Speed Air-Jet-Assisted Machining of Inconel 718

2017 ◽  
Vol 749 ◽  
pp. 87-93
Author(s):  
Toshiyuki Obikawa ◽  
Masashi Yamaguchi
Keyword(s):  
Inconel 718 ◽  
High Speed ◽  
Cutting Speed ◽  
Cutting Performance ◽  
Necessary Condition ◽  
Nickel Base Superalloy ◽  
Ceramic Tool ◽  
Air Jet ◽  
Nickel Base ◽  
Base Superalloy

This paper describes the high speed air-jet-assisted machining of nickel-base superalloy with a SiC whisker reinforced alumina insert. This machining method showed already good performance in high speed machining of Inconel 718. In this paper, the influence of the application direction of coolant on the tool wear and tool life was investigated for obtaining much better cutting performance of the ceramic tool. The coolant was applied from the side of flank face with three different directions: two oblique directions from the end and side flank faces and the perpendicular direction to the cutting edges. In contrast, the application direction of the air jet was always perpendicular to the cutting edges. The experimental results showed that the best performance in the air-jet-assisted machining was obtained by applying coolant from the side of side flank at a cutting speed of 420 m/min and from the side of end flank at a cutting speed of 780 m/min. The necessary condition found for the best performance was that the size of notch wear was a little larger than that of flank wear.

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