Submicrometer Cutting Tools on the Basis of Al2O3 for Machining Alloyed Hard Cast Iron and Hardened Steel

Author(s):  
Andreas Krell ◽  
Paul Blank ◽  
Lutz-Michael Berger ◽  
Volkmar Richter
2018 ◽  
Vol 108 (11-12) ◽  
pp. 773-777
Author(s):  
E. Uhlmann ◽  
J. Polte ◽  
M. Polte ◽  
Y. Kuche ◽  
H. Wiesner

Die Mikrozerspanung ist eine Kerntechnologie bei der Fertigung von Mikrospritzgussformen. Die hohen Ansprüche an die geometrische Genauigkeit und Oberflächenrauheit erfordern den Einsatz hochfester Werkstoffe. Jedoch unterliegen aktuelle Fräswerkzeuge bei der Mikrozerspanung einem hohen Verschleiß. Einen Lösungsansatz bietet der erfolgreich in der Makrozerspanung eingesetzte Schneidstoff kubisch-kristallines Bornitrid (cBN). Ziel der Untersuchungen war es daher, detaillierte Informationen zur Bearbeitung von gehärtetem Stahl mit cBN-Mikrofräswerkzeugen bereitstellen zu können.   Micro-cutting is a core technology for producing micro-injection moulds. High demands on geometric accuracy and surface roughness require high-strength materials. However, current milling tools for micro-cutting suffer from excessiv tool wear. A solution is offered by cutting materials based on cubic Boron Nitride (cBN), which have been used successfully in macro-machining. This article contains detailed information on the machining of hardened steel with micro-milling tools and cutting edges made of cBN.


1999 ◽  
Author(s):  
Katsuhito Yoshida ◽  
Satoru Kukino ◽  
Takashi Harada ◽  
Tomohiro Fukaya ◽  
Junichi Shiraishi ◽  
...  

Abstract PCBN (Polycrystalline Cubic Boron Nitride) cutting tools have become very familiar in the industries for cutting hardened steel parts and the demand for PCBN tools is growing rapidly. One of the reasons for this is the trend of replacing grinding processes with cutting. Although the trend of processing is to use more cutting, there still remains grinding in many processing fields. High precision machining and high speed interrupted machining have been such fields. In this study it has been verified that a novel cutting method can be applied to high precision machining with the smoothness of Rz 0.8 μm and that a new PCBN has sufficient reliability against tool failure in high speed (< 250m/min) interrupted cutting. Thus cutting has become applicable to those machining and the trend of replacement of grinding with cutting will be enhanced. Those new technologies will be introduced in this report.


2018 ◽  
Vol 777 ◽  
pp. 393-396
Author(s):  
Xin Yu Song ◽  
Guo Chen Du

In modern steel industry, hardened steel rolls are very important tools. The increase of the automobile and the mould keeps the amount of rolls increases fairly quickly. In cutting process, hardened rolls are very difficult to turn or mill, there for, almost all hardened rolls are cut only by grinding, which causes low efficiency, besides in grinding process and a lot of cutting fluid are used. In this paper, surface roughness of workpiece was analyzed of the ceramic tools in different cutting conditions. Wear machanism of crack and abrasive of cutting tools were also analyzed. The experimental and theoretical analysis confirmed that when the ceramic tools cutting cold rolls, the generation and expansion of the cracks the most important role that affect tool life and workpiece surface roughness.


2010 ◽  
Vol 660-661 ◽  
pp. 106-111
Author(s):  
José Vitor C. Souza ◽  
Maria do Carmo de Andrade Nono ◽  
João Paulo Barros Machado ◽  
Olivério Moreira Macedo Silva ◽  
F.C.L. Melo ◽  
...  

Silicon nitride cutting tools have been used successfully for machining hard materials, like: cast irons, nickel based alloys, etc. However these cutting tools with diamond coating present little information on dry turning operations of gray cast iron. In the present work, Si3N4 square inserts was developed, characterized and subsequently coated with diamond for dry machining operations on gray cast iron. All experiments were conducted with replica. It was used a 1500, 3000, 4500 m cutting length, feed rate of 0.33 mm/rev and keeping the depth of cut constant and equal to 1 mm. The results show that wear in the tool tips of the Si3N4 inserts, in all cutting conditions, was caused by both mechanical and chemical processes. To understand the tool wear mechanisms, a morphological analysis of the inserts, after experiments, has been performed by SEM and optical microscopy. Diamond coated PVD inserts showed to be capable to reach large cutting lengths when machining gray cast iron.


2002 ◽  
Vol 124 (4) ◽  
pp. 820-832 ◽  
Author(s):  
Jiancheng Liu ◽  
Kazuo Yamazaki ◽  
Hiroyuki Ueda ◽  
Norihiko Narutaki ◽  
Yasuo Yamane

In order to increase the accurate finishing productivity of pearlitic cast iron, face milling by CBN (Cubic Boron Nitride) cutting tools was studied. The main focus of the study is the machinability investigation of pearlitic cast iron with CBN cutting tools by studying the relationships among machining conditions such as feed rate, cutting speed as well as CBN cutting tool type, tool wear, workpiece surface quality, cutting forces, and cutting temperature. In addition, an emphasis is put on the effect of Al additive in pearlitic cast iron on its machinability and tool wear characteristics. High-speed milling experiments with CBN cutting tools were conducted on a vertical machining center under different machining conditions. The results obtained provide a useful understanding of milling performance by CBN cutting tools.


2008 ◽  
Vol 591-593 ◽  
pp. 565-571 ◽  
Author(s):  
Olivério Moreira Macedo Silva ◽  
Maria do Carmo de Andrade Nono ◽  
José Vitor C. Souza ◽  
M.V. Ribeiro

The α-SiAlON ceramic cutting tool insert is developed. Silicon nitride and additives powders are pressed and sintered in the form of cutting tool inserts at temperature of 1900 oC. The physics and mechanical properties of the inserts like green density, weight loss, relative density, hardness and fracture toughness are evaluated. Machining studies are conducted on grey cast iron workpiece to evaluate the performance of α-SiAlON ceramic cutting tool. In the paper the cutting tool used in higher speed showed an improvement in the tribological interaction between the cutting tools and the grey cast iron workpiece resulted in a significant reduction of flank wear and roughness, because of better accommodation and the presence of the graphite in gray cast iron. The above results are discussed in terms of their affect at machining parameters on gray cast iron.


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