PCBN Tool Wear Mechanism in Hard Turning Hardened Bearing Steel

2006 ◽  
Vol 315-316 ◽  
pp. 334-338 ◽  
Author(s):  
S.J. Dai ◽  
Dong Hui Wen ◽  
Ju Long Yuan

The wear pattern and mechanism during continuous hard turning GCr15 hardened bearing steel with BZN8200 PCBN cutting tool was studied. Experimental results showed that the main wear pattern is crater wear in rake face and mechanical wear in flank face, the main wear mechanism is made-up with adhesive, oxidization and diffusive wear. The adhesive wear is generated by melt workpiece material flows with binder material of PCBN tool during initial cutting, oxidative wear is derived by cutting temperature and pressure of cutting zone when the flank wear increase after initial cutting, diffusive wear phenomenon is the absolute mechanism with the diffusive effect between workpiece and tool material in final cutting time.

Author(s):  
Aruna Prabha Kolluri ◽  
Srinivasa Prasad Balla ◽  
Satya Prasad Paruchuru

Abstract The 3D Finite element method (FEM) is an efficient tool to predict the variables in the cutting process, which is otherwise challenging to obtain with the experimental methods alone. The present study combines both experimental findings and finite element simulation outcomes to investigate the effect of tool material on output process variables, such as vibrations, cutting temperature distribution and tool wear mechanism. Machining of popular aerospace materials like Ti-6Al-4V and Al7075 turned with coated and uncoated tools are part of the investigation. The authors choose the orthogonal test, measured vibrations and cutting temperatures and used FE simulations to carry out the subsequent validations. This study includes the influence of the predicted heat flux and temperature distribution on the tool wear mechanism. The main aim of this study is to investigate the performance quality of uncoated and coated carbide tools along with its thermal aspects. Comparison of experiment and simulation outcomes shows good agreement with a maximum error of 9.02%. It has been noted that the increase of cutting temperature is proportional to its cutting speed. As the cutting speed increases, it is observed that vibration parameter and flank wear value also increases. Overall, coated carbide turning insert tool is the best method for metal turning with higher rotational speeds of the spindle.


2006 ◽  
Vol 315-316 ◽  
pp. 329-333 ◽  
Author(s):  
Lu Xiao ◽  
M.X. Zeng ◽  
Dong Hui Wen ◽  
H.H. Wu ◽  
B.H. Si

The wear behaviour in the precision interrupted hard part turning SAE8822 case hardened steel by BN250 PCBN cutting tool was studied. Experimental results showed that the main wear mechanism for the PCBN tool was the edge chipping by the fluctuation of cutting forces and cutting temperature. The oxidization and diffusion of the elements between workpiece and PCBN tool decrease the bonded strength between binder and cBN crystal, then lead to the damage of PCBN cutting tool.


2013 ◽  
Vol 631-632 ◽  
pp. 681-685
Author(s):  
Fang Shao ◽  
Fa Qing Li ◽  
Hai Ying Zhang ◽  
Xuan Gao

Aero-engine alloys (also as known as superalloys)are known as difficult-to-machine materials, especially at higher cutting speeds, due to their several inherent properties such as low thermal conductivity and their high reactivity with cutting tool materials. In this paper a finite element analysis (FEA) of machining for Incoloy907 is presented. In particular, the thermodynamical constitutitve equation(T-C-E) in FEA is applied for both workpiece material and tool material. Cutting temperature and cutting force are predicted. The comparison between the predicted and experimental cutting temperature and cutting force are presented and discussed. The results indicated that a good prediction accuracy of both principal cutting temperature and cutting force can be achieved by the method of FEA with thermodynamical constitutitve equation.


2014 ◽  
Vol 538 ◽  
pp. 54-57
Author(s):  
Fang Shao ◽  
Yu Ting Wang ◽  
Li Jing Zou ◽  
Yan Ying Wu ◽  
Dong Sun

Cutting temperature always highly reaches over to 1000°C when high speed machining with PCBN tools. Diffusion of tool material element may have important influence on tool wear at such high temperature, the diffusion wear and oxidation wear have become the major wear mechanism. In this paper, the rules of diffusion wear and oxidation wear for PCBN cutting tools are proposed and analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpice materials of PCBN tool material at different temperature are then calculated. Diffusion reaction rules in high temperature are developed and analyzed using Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2 and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data; the results will provide useful references for tool material design and selection.


2013 ◽  
Vol 634-638 ◽  
pp. 1790-1793
Author(s):  
Fang Shao ◽  
Hai Ying Zhang ◽  
Zhi Jun Fan

Aero-engine alloys (also as known as superalloys)are known as difficult-to-machine materials, especially at higher cutting speeds, due to their several inherent properties such as low thermal conductivity and their high reactivity with cutting tool materials. In this paper a finite element analysis (FEA) of machining for Incoloy907 is presented. In particular, the thermodynamical constitutitve equation(T-C-E) in FEA is applied for both workpiece material and tool material. Cutting temperature and cutting force are predicted. The comparison between the predicted and experimental cutting temperature and cutting force are presented and discussed. The results indicated that a good prediction accuracy of both principal cutting temperature and cutting force can be achieved by the method of FEA with thermodynamical constitutitve equation.


2013 ◽  
Vol 589-590 ◽  
pp. 128-133
Author(s):  
Fang Shao ◽  
Yu Ting Wang ◽  
Li Jing Zou ◽  
Xue Yan ◽  
Yan Ying Wu

Cutting temperature always highly reaches over to 1000°C ? when high speed machining with PCBN tools. Diffusion of tool material element may have important influence on tool wear at such high temperature; the diffusion wear and oxidation wear have become the major wear mechanism. In this paper, the rules of diffusion wear and oxidation wear for PCBN cutting tools are proposed and analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpiece materials of PCBN tool material at different temperature are then calculated. Diffusion reaction rules in high temperature are developed and analyzed using Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2 and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data; the results will provide useful references for tool material design and selection.


2016 ◽  
Vol 45 (8) ◽  
pp. 806002
Author(s):  
张昌娟 Zhang Changjuan ◽  
焦 锋 Jiao Feng ◽  
牛 赢 Niu Ying

Author(s):  
Linwen Li ◽  
Bin Li ◽  
Xiaochun Li ◽  
Kornel F. Ehmann

Temperature-distribution measurements in cutting tools during the machining process are extremely difficult and remain an unresolved problem. In this paper, cutting temperature distributions are measured by thin film thermocouples (TFTCs) embedded into Polycrystalline Cubic Boron Nitride (PCBN) cutting inserts in the immediate vicinity of the tool-chip interface. Using these measurements, steady and dynamic phenomena during hard turning as well as the chip morphology and formation process were analyzed based on the cutting temperature distributions in the insert. The relationship between the cutting temperature-field distributions in the PCBN insert and the segmented chip formation is analyzed using temperature-distribution mapping. It is shown that the temperature-distribution in the cutting zone depends on the shearing band distribution in the chip and the thermal transfer rate from the heat generation zone to the cutting tool. Furthermore, it became evident that the material flow stress and the shearing bands greatly affect not only the chip formation morphology but also the cutting temperature field distributions in the cutting zone of the cutting insert.


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