Evaluation of Silicon Nitride Ceramic Cutting Tools with Diamond Coatings

2008 ◽  
Vol 591-593 ◽  
pp. 537-542 ◽  
Author(s):  
M.A. Lanna ◽  
A.M. Abrão ◽  
F. Levy Neto ◽  
Claudinei dos Santos ◽  
Cosme Roberto Moreira Silva
Keyword(s):  
Silicon Nitride ◽  
Flank Wear ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Carbon Powder ◽  
Diamond Coating ◽  
Machining Performance ◽  
Film Rupture ◽  
Composite Surface ◽  
Ceramic Tools

There is a substantial increase on carbon-carbon composites use for engineering applications, considering its high temperature properties and low specific mass. However the machining costs are relatively high, and new cutting tools, mainly ceramics, must be developed to overcome such difficulty, aiming cost reductions. In this work, silicon nitride based ceramics has been prepared , by pressureless sintering of silicon nitride powders and appropriate amounts of Al2O3,Ce2O3, Y2O3 and AlN. Cutting tools were prepared from the sintered materials, with geometry according to ISO1832. Selected cutting tools were also diamond coated by a hot filament-assisted Chemical Vapor Deposition (HFCVD) diamond coating process. Carbon Fiber Reinforced Carbon (CFRP) composites machining was performed, to evaluate the diamond coating influence on machining performance. After the tests, the uncoated tools presented severe flank wear and shorter life than the diamond coated ceramic tools. This flank wear is caused by the abrasive carbon powder generated during the facing operation. On CVD diamond coated α-SiAlON ceramic tools, no flank wear was observed, and the cutting edge remained unmodified, even for severe test conditions, such as high cutting length and speed. Carbon particles, originated from the machined composite, do not promotes diamond film rupture, but instead, acts as lubricant film and reduces composite surface initial roughness.

Comparative Studies on the Cutting Performance of CVD Diamond and DLC Coated Inserts in Turning GFRP Composite Materials

2010 ◽  
Vol 431-432 ◽  
pp. 466-469
Author(s):  
Dong Can Zhang ◽  
Bin Shen ◽  
Fang Hong Sun ◽  
Ming Chen ◽  
Zhi Ming Zhang
Keyword(s):  
Composite Materials ◽  
Flank Wear ◽  
Arc Discharge ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cutting Performance ◽  
Vacuum Arc ◽  
Reinforced Plastics ◽  
Gfrp Composite

The diamond and diamond-like carbon (DLC) films were deposited on the cobalt cemented tungsten carbide (WC-Co) cutting tools respectively adopting the hot filament chemical vapor deposition (HFCVD) technique and the vacuum arc discharge with a graphite cathode. The scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD) and Raman spectroscopy were used to characterize the as-deposited diamond and DLC films. To evaluate their cutting performance, comparative turning tests were conducted using the uncoated WC-Co and as-fabricated CVD diamond and DLC coated inserts, with glass fiber reinforced plastics (GFRP) composite materials as the workpiece. The research results exhibited that diamond and DLC coated inserts had great advantages in cutting tests compared to uncoated insert. The flank wear of the CVD diamond coated insert maintained a very low value about 50μm before the cutting tool failure occurred. For the DLC coated insert, its flank wear always maintained a nearly constant value of 70~200μm during whole 45 minutes turning process. The flank wear of CVD diamond coated insert was lower than that of DLC coated insert before diamond films peeling off.

Experimental Study on the Cutting Performance of TiC-Based Nanocomposite Ceramic Tools in Turning 40Cr Steel

2011 ◽  
Vol 325 ◽  
pp. 309-314
Author(s):  
Han Lian Liu ◽  
Ming Hong ◽  
Chuan Zhen Huang ◽  
Bin Zou
Keyword(s):  
Flank Wear ◽  
Adhesive Wear ◽  
Cutting Tools ◽  
Cutting Performance ◽  
Rake Face ◽  
Ceramic Tool ◽  
Tool Materials ◽  
Ceramic Tools ◽  
Multi Scale ◽  
40Cr Steel

TiC-based ceramic cutting tools with three different particle size levels of Al2O3 additives were fabricated and tested. Theses tool materials were identified as TA, TA10A5 and TA30A5 respectively in this study. Another commercial cutting material identified as LT55 was used in this study as baseline to investigate cutting performance by comparing the flank wear size. The experimental results showed that multi-scale nanocomposite ceramic tool TA10A5 had much better wear resistance than the other tools when turning at a lower speed. The wear mechanisms were mainly adhesive wear in the rake face. While cutting at a higher speed, the breakage failure occurred for the tools TA10A5 and TA30A5.

Stress in Diamond Coatings on Cutting Tools Deposited by Hollow Substrate Holder

2009 ◽  
Vol 407-408 ◽  
pp. 19-23
Author(s):  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Feng Xu ◽  
Chun Yang ◽  
Min Wang
Keyword(s):  
Substrate Temperature ◽  
Carbon Content ◽  
Compressive Stress ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Substrate Holder ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Ch4 Concentration

Chemical vapor deposition (CVD) diamond coatings were deposited on milling cutter substrate using a hollow substrate holder. The substrate is WC–Co cemented carbide contained 6% of cobalt concentration. Structures and stress state of diamond films were analyzed by scanning electron microscopy (SEM) and Raman spectroscopy. It was found that the diamond coating is of the same quality at the same cutting tool deposited on a hollow substrate holder. Diamond (sp3) bonds are better developed with substrate temperature of ~760°C. A higher or lower substrate temperature could lead to a higher non-diamond carbon content in the films. A higher substrate temperature could lead to a higher thermal stress. The compressive stress increases when the substrate temperature is higher or lower than 760°C. The concentration of amorphous phase in the coatings is low with CH4 concentration of 1.0% and 1.5%. A higher non-diamond carbon content and defects in the diamond coatings increase with the increase of CH4 concentration, which leads to the compressive stress value does not increase significantly under a high CH4 concentration.

Machining Performance of CBN Cutting Tools for Hard Turning of 100Cr6 Bearing Steel

2014 ◽  
Vol 474 ◽  
pp. 333-338
Author(s):  
János Kundrák ◽  
László Ráczkövi ◽  
Károly Gyáni
Keyword(s):  
Hard Turning ◽  
Flank Wear ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Bearing Steel ◽  
Cutting Performance ◽  
Machining Performance ◽  
Technological Parameters ◽  
Wear Rates ◽  
Material Volume

This article presents the examination of cutting performance of a low CBN content cutting tool in the case of hard turning of 100Cr6 hardened bearing steel. One of the indicators of cutting performance is the wear rate, which can be calculated as a ratio of a measurable geometric parameter of a wear form and some technological parameters (cutting time, cutting length or removed material volume). The wear of CBN cutting tools is characterized by the extent of flank wear hence the wear rates related to cutting time and removed material volume are calculated based on the measured flank wear during the cutting experiments. The alteration of wear rates as a function of flank wear and cutting speed was examined.

scholarly journals Performance Comparison of Al2O3 Cutting Tool with and without Reinforcement of Graphene Nanoplatelets

2021 ◽  
Vol 10 (3) ◽  
pp. 93-96
Author(s):  
A.Gopala Krishna ◽  
R Peddi Raju
Keyword(s):  
Fracture Toughness ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Tool Material ◽  
Performance Comparison ◽  
Graphene Nanoplatelets ◽  
Cnc Machining ◽  
Machining Performance ◽  
Composite Tool

Al2O3 is a commonly used cutting tool material for machining cast iron and hard steels. However its low fracture toughness has been its potential drawback to use it for wider applications. In order to improve the fracture toughness, graphene nanoplatelets has been used as the reinforcement. The Al2O3 -TiCN composite have been made by powder metallurgy. The present work compares the performance characteristics of Al2O3 -TiCN with and without graphene nanoplatelets (GNP) in CNC machining. The machining performance of the prepared cutting tools is tested in terms of temperature generated, flank wear, cutting force and surface finish. It is observed that the prepared composite tool with GNP has much improved machining performance over the Al2O3 cutting tool that has no GNP reinforcement. The work has the unique novelty of using GNP as the reinforcement in Al2O3 cutting tool material

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

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