Thermal Plasticity Index of Nanostructured N-Based Coatings on HSS 6-5-2 (1.3343) Tool Steel

2016 ◽  
Vol 879 ◽  
pp. 262-267
Author(s):  
Marcello Cabibbo ◽  
Nicola Clemente ◽  
Farayi Musharavati ◽  
Stefano Spigarelli
Keyword(s):  
Thermal Stability ◽  
Tool Steel ◽  
Cutting Tools ◽  
Plasticity Index ◽  
Temperature Oxidation ◽  
Pressure Limit ◽  
Thermal Plasticity ◽  
Specific Contact ◽  
Continuous Index ◽  
Thermal Stability Of

Nowadays, cutting tools, designed to be used for machining without lubricants, are developed to improve the high working speed capabilities. With this respect, quaternary Ti-and N-based coatings are able to significant increase hardness, wear resistance and high temperature oxidation resistance. One of the major drawbacks still consists on the limited thermal stability of such coatings, which is reported to be about 600°C. In the present study, thermal stability studies of a nanostructured multi-layered N-based (AlTiCrxN1-x) coating on a HSS 6-5-2 tool steel were carried out. Two quantities were calculated out of the hardness and elastic modulus of the coatings. One is the ratio H/E that represents the coating resistance to compression without failure; another one is H3/E2, which provides information on the specific contact pressure limit without failure. It was found that, by using the less demanding thermal cycling mode, the coating ability to plastically deform without damage, is retained up to 800-1000°C. The highest, and more effective coating plasticity index was obtained by using the less demanding cycling mode, while, the other two modes induced a continuous index decrease with temperature.

Effect of Chemistry Modification, Hot Forging and Partitioning on Low Alloy Grade Tool Steel

2018 ◽  
Vol 786 ◽  
pp. 75-83
Author(s):  
Ahmed Ismail Zaky Farahat ◽  
Mohamed Kamal El Fawkhry ◽  
Ayman M. Fathy ◽  
Taha M. Mattar
Keyword(s):  
Thermal Stability ◽  
Tool Steel ◽  
Retained Austenite ◽  
Treatment Process ◽  
Hot Forging ◽  
Optical Microscope ◽  
Isothermal Treatment ◽  
The Novel ◽  
Slow Cooling ◽  
Thermal Stability Of

Development of S6 tool steel has been discussed in this research by conducting a bit modification in the chemical composition using aluminum instead of molybdenum, and micro addition of boron to enhance the marteniste structure. Then, the hardenability and thermal stability have been detected in regarding to S6 tool steel. A novel isothermal treatment process has been suggested to enrich the retained austenite, and thereby, it has been tracked by using XRD, optical microscope, and SEM in conjugation with EDS. The effect of retained on the mechanical properties has been determined. The results ensure that aluminum has inhibited the graphite formation through the slow cooling regime. No change of hardenability or thermal stability of S6 tool steel triggered from adding of aluminum and microaddition of boron. In addition, the novel isothermal process leads to enrichment of retained austenite that has significantly affected on the combination of ductility with strength of the newly designed steel.

scholarly journals Microstructure, Mechanical Properties, and Thermal Stability of Carbon-Free High Speed Tool Steel Strengthened by Intermetallics Compared to Vanadis 60 Steel Strengthened by Carbides

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1901
Author(s):  
Alena Michalcová ◽  
Vojtěch Pečinka ◽  
Zdeněk Kačenka ◽  
Jan Šerák ◽  
Jiří Kubásek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tool Steel ◽  
High Speed ◽  
Intermetallic Phase ◽  
High Hardness ◽  
Thermal Exposure ◽  
Machining Process ◽  
Material Utilization ◽  
Thermal Stability Of

High speed tool steels are materials that exhibit superior mechanical properties (e.g., high hardness). They should also be resistant to thermal exposure to maintain high hardness during the machining process. In this paper, a C-free tool steel formed of Fe matrix and a Mo6Co7 intermetallic phase was studied. This steel was compared to the well-known Vanadis 60 steel containing Fe matrix and carbides. Microstructures were investigated by scanning (SEM) and transmission (TEM) electron microscopy, and the mechanical properties and thermal stability of both materials were compared. It was proven that the strengthening in the Vanadis 60 steel was mainly caused by the carbides, while the C-free steel was strengthened by the Mo6Co7 phase. The hardness values of both materials were comparable in the utilization state (approx. 950 HV). The hardness of Vanadis 60 steel decreased after several minutes of annealing at 650 °C under the value that enables material utilization. The hardness value of the steel strengthened by the intermetallics also decreased but significantly slower. Based on these results, the main finding of this study is that the C-free steel exhibited much better thermal stability and may be utilized at higher temperatures for longer periods of time than Vanadis 60.

Thermal Stability of Ohmic Contacts to n-InxGa1−xN

1995 ◽  
Vol 395 ◽  
Author(s):  
A. Duibha ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
J. W. Lee ◽  
P. H. Holloway ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electron Spectroscopy ◽  
Ohmic Contacts ◽  
Electrical Characteristics ◽  
Microstructural Properties ◽  
Excellent Thermal Stability ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Thermal Stability Of

ABSTRACTThe microstructural properties and interdiffusion reactions of Au/Ge/Ni, Ti/Pt/Au, WSix and AuBe contacts on GaN and In0.5Ga0.5N have been examined using Scanning Electron Microscopy and Auger Electron Spectroscopy. The WSix contacts possess excellent thermal stability and retained good structural properties at annealing temperatures as high as 800°C on GaN. The electrical characteristics of WSix contacts on In0.5Ga0.5N had a specific contact resistivity of 1.48×10−5Ωcm2 and an excellent surface morphology following annealing at 700°C. The increase in contact resistance observed at higher temperatures was attributed to intermixing of metal and semiconductor. In contrast the Ti/Pt/Au and Au/Ge/Ni contacts were stable only to ≤ 500°C. AuBe contacts had the poorest thermal stability, with substantial reaction with GaN occurring even at 400°C. The WSix contact appears to be an excellent choice for high temperature GaN electronics applications.

Thermal stability of metastable austenite in rapidly solidified chromium–molybdenum–vanadium tool steel powder

2004 ◽  
Vol 375-377 ◽  
pp. 581-584 ◽  
Author(s):  
P. Grgac ◽  
R. Moravcik ◽  
M. Kusy ◽  
I. Toth ◽  
M. Miglierini ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Tool Steel ◽  
Steel Powder ◽  
Metastable Austenite ◽  
Rapidly Solidified ◽  
Thermal Stability Of
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