Monitoring life of diamond tool in ultra-precision machining

2015 ◽  
Vol 82 (5-8) ◽  
pp. 1141-1152 ◽  
Author(s):  
C. Y. Chan ◽  
L. H. Li ◽  
W. B. Lee ◽  
H. C. Wong
Author(s):  
Shaojian Zhang ◽  
Pan Guo ◽  
Zhiwen Xiong ◽  
Suet To

Shear angle is classically considered constant. In the study, a series of straight orthogonal cutting tests of ultra-precision machining revealed that shear angle cyclically evolved with each lamellar chip formation, i.e. cyclic shear angle. It grew up from an initial shear angle of 0° to a final shear angle 90°- α ( α: tool rake angle) and underwent a series of transient shear angles like classical shear angles and a critical shear angle. The critical shear angle is the sum of the half of the tool rake angle and the characteristic shear angle determined by material anisotropy without the friction effect. Moreover, a new model was developed. Further, a series of face turning tests of ultra-precision machining verified that the cyclic shear angle was the intrinsic mechanism of cyclic cutting forces and lamellar chip formation to induce twin-peak high-frequency multimode diamond-tool-tip vibration. Significantly, the study draws up an understanding of shear angle for the discrepancy among the classical models.


2009 ◽  
Vol 407-408 ◽  
pp. 359-362 ◽  
Author(s):  
Takehisa Yoshikawa ◽  
Masayuki Kyoi ◽  
Yukio Maeda ◽  
Tomohisa Ohta ◽  
Masato Taya

Patterning of numerous microlenses on a surface improves the optical performance of components such as liquid crystal displays. A cutting method using a diamond tool is examined to fabricate a molding die that employs arbitrary array patterns to mold millions of microlenses. The present paper investigates machining of microlenses on the order of 2 kHz, using a piezo-actuated micro cutting unit and a synchronous control system of the cutting unit with an NC controller. Experiments using this system revealed that it is possible to machine a large number of microlenses on a molding die with high precision.


Author(s):  
Changlin Liu ◽  
Jianning Chu ◽  
Jinyang Ke ◽  
Xiao Chen ◽  
Jianguo Zhang ◽  
...  

Abstract Silicon carbide (SiC) is a material of great interest in many industrial applications. However, due to the hardness and brittleness nature, achieving ultra-precision machining of SiC is still challenging. In recent years, function surface with micro-structures has been introduced in cutting tool to suppress wear process. But the wear mechanism of the structured tool has not been revealed completely. Therefore, in present research, molecular dynamic simulations were conducted to investigate the influence of the micro-structure on the nano scale cutting process of 3C-SiC. The simulation results showed that the dislocation propagation in workpiece can be suppressed with a structured tool. The micro-structures have a great influence on the stress distribution in the workpiece subsurface. Furthermore, the abrasive wear of the structured tool is obvious smaller since the edges of the tool became blunt and the contact face between tool and workpiece changed to the close-packed plane of diamond. Moreover, the amorphization of the structured tool is effectively suppressed. This study contributes to the understanding of the details involved in the ultra-precision cutting of SiC.


2012 ◽  
Vol 06 ◽  
pp. 583-588
Author(s):  
Geon Lee ◽  
Sung-Hyun Kim ◽  
Nam-Su Kwak ◽  
Jae-Yeol Kim

The ultra-precision products which recently experienced high in demands had included the large areas of most updated technologies, for example, the semiconductor, the computer, the aerospace, the media information, the precision machining. For early 21st century, it was expected that the ultra-precision technologies would be distributed more throughout the market and required securing more nation-wise advancements. Furthermore, there seemed to be increasing in demand of the single crystal diamond tool which was capable of the ultra-precision machining for parts requiring a high degree of complicated details which were more than just simple wrapping and policing. Moreover, the highest degree of precision is currently at 50nm for some precision parts but not in all. The machining system and technology should be at very high preformed level in order to accomplish this degree of the ultra-precision.


2012 ◽  
Vol 516 ◽  
pp. 293-298 ◽  
Author(s):  
Jen Osmer ◽  
Ralf Gläbe ◽  
Ekkard Brinksmeier

For the replication of optical glass or plastic components moulding inserts with surface roughness in the nanometre range and form accuracy in the micron or sub-micron range are needed. Despite these requirements the applied moulding insert material has to suit further needs like high temperature stability and resistivity against abrasive and chemical wear. To satisfy the specific requirements of replication processes steel alloys can be heat treated in a way to meet these demands. Unfortunately, these steel alloys cannot be machined with single crystal diamond tools because catastrophic diamond tool wear occurs. In recent years good progress in the field of ultra precision machining of steel has been made by nitrocarburizing the steel alloy. This leads to a sub-surface compound layer which is diamond machinable with surface roughness Sa < 10 nm and reduced diamond tool wear. But the ultra precision machining of these nitrocarburized steels introduces new challenges caused by the high hardness of the compound layer. Typical values are about 1200HV0.025. Therefore, this paper presents results from ultra precision machining processes focusing on the material behaviour during the cutting process. Influences of depth of cut and material composition on the surface generation can be found by evaluating chip formation and the resulting chips. Furthermore, the sub-surface of ultra precision machined steels is characterized by metallographic analysis to evaluate the influence of the nitrocarburizing process on ultra precision machining. In conclusion this paper presents the results for a deeper understanding of the material removal mechanisms in ultra precision machining of nitrocarburized steels.


Author(s):  
Liu Changglin ◽  
Jianning Chu ◽  
Jinyang Ke ◽  
Xiao Chen ◽  
Jianguo Zhang ◽  
...  

Abstract Silicon carbide (SiC) is an important material in many industrial applications. However, due to the hardness and brittleness nature, achieving ultra-precision machining of SiC is still challenging. In recent years, function surface with micro-structures has been introduced in cutting tool to suppress wear process. But the wear mechanism of the structured tool has not been revealed completely. Therefore, in present research, molecular dynamic simulations were conducted to investigate the cutting performance of the micro-structure on the nano scale cutting process of 3C-SiC. The simulation results showed that the dislocation propagation in workpiece can be suppressed with a structured tool. The micro-structures have a significant influence on the stress distribution in the workpiece subsurface. Furthermore, the abrasive wear of the structured tool is obvious smaller since the edges of the tool became blunt and the contact face between tool and workpiece changed to the close-packed plane of diamond. Moreover, the amorphization of the structured tool is effectively suppressed. This study contributes to the understanding of the material behavior involved in the ultra-precision cutting of SiC.


2019 ◽  
Vol 18 ◽  
pp. 1510-1516
Author(s):  
Garima Singh ◽  
Vinod Mishra ◽  
Vinod Karar ◽  
S.S Banwait

2011 ◽  
Vol 211 (12) ◽  
pp. 2152-2159 ◽  
Author(s):  
Yilong Wang ◽  
Qingliang Zhao ◽  
Yuanjiang Shang ◽  
Pengxiang Lv ◽  
Bing Guo ◽  
...  

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