Synthesis and Characterization of Nanocrystalline M50 Steel Powders by Cryomilling

1995 ◽  
Vol 400 ◽  
Author(s):  
M. L. Lau ◽  
B. Huang ◽  
R. J. Perez ◽  
S. R. Nutt ◽  
E. J. Lavernia
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
High Energy ◽  
Average Grain Size ◽  
Energy Ball ◽  
Nanocrystalline Microstructure ◽  
Al Powder ◽  
Thermal Stability Of ◽  
M50 Steel

AbstractThe present study investigated the synthesis of nanocrystalline high speed steel M50 (4.5% Mo, 4.0% Cr, 1.0% V, 0.8% C, balance Fe) by cryogenic high energy ball milling (cryomilling). Pre-alloyed M50 steel was spray atomized, and subsequently cryomilled in liquid nitrogen for 25 hours. Elemental Al powder was added prior to cryomilling in order to promote the formation of nanoscale Al2O3 and AlN particles, which improved the thermal stability of the nanocrystalline M50 steel. Following annealing at 1373 K, the M50 steel was found to retain its nanocrystalline microstructure with the average grain size of 40–80 nm.

Thermodynamic Calculation and Characterization of Carbide Precipitation in Laser-Deposited Material for High-Speed Steel Alloy

2021 ◽  
Vol 30 (3) ◽  
pp. 1825-1837
Author(s):  
Ali Jammal ◽  
Gang Wang ◽  
Hanbo Yang ◽  
Songge Yang ◽  
Yu Zhong ◽  
...  
Keyword(s):  
Thermodynamic Calculation ◽  
High Speed ◽  
High Speed Steel ◽  
Carbide Precipitation ◽  
Steel Alloy

Synthesis and Characterization of CNT Reinforced AA4032 Nanocomposites by High Energy Ball Milling

2010 ◽  
Author(s):  
M. S. Senthil Saravanan ◽  
K. Sivaprasad ◽  
S. P. Kumaresh Babu ◽  
P. Susila ◽  
B. S. Murty ◽  
...  
Keyword(s):  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Synthesis And Characterization ◽  
Energy Ball

scholarly journals Processing and microstructural characterization of a Ti-Cr-Nb alloy synthesized by high-energy ball-milling

2012 ◽  
Vol 15 (5) ◽  
pp. 753-756 ◽  
Author(s):  
José Fernando Ribeiro de Castro ◽  
Sydney Ferreira Santos ◽  
Tomaz Ishikawa ◽  
Walter José Botta
Keyword(s):  
Ball Milling ◽  
Microstructural Characterization ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball

Tribological Characterization of Machining at Very Small Contact Areas

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Michael R. Lovell ◽  
P. Cohen ◽  
Pradeep L. Menezes ◽  
R. Shankar
Keyword(s):  
High Speed ◽  
Friction Mechanisms ◽  
High Speed Steel ◽  
Small Scale ◽  
Machining Processes ◽  
Macroscopic Theory ◽  
Contact Areas ◽  
Tribological Characterization ◽  
Physical Phenomena

When machining miniaturized components, the contact conditions between the tool and the workpiece exhibit very small contact areas that are on the order of 10−5 mm2. Under these conditions, extremely high contact stresses are generated, and it is not clear whether macroscopic theories for the chip formation, cutting forces, and friction mechanisms are applicable. For this reason, the present investigation has focused on creating a basic understanding of the frictional behavior in very small scale machining processes so that evaluations of standard macroscale models could be performed. Specialized machining experiments were conducted on 70/30 brass materials using high-speed steel tools over a range of speeds, feeds, depths of cut, and tool rake angles. At each operating condition studied, the friction coefficient and the shear factor τk were obtained. Based on the experimental results, it was determined that the standard macroscopic theory for analyzing detailed friction mechanisms was insufficient in very small scale machining processes. An approach that utilized the shear factor, in contrast, was found to be better for decoupling the physical phenomena involved. Utilizing the shear factor as an analysis parameter, the parameters that significantly influence the friction in microscale machining processes were ascertained and discussed.

Thermal Spraying Applied Onto High Energy Railway Braking: Characterization of Friction Performances

1998 ◽  
Author(s):  
H. Bartys ◽  
J.D. Guerin ◽  
J.P. Bricout ◽  
J. Oudin
Keyword(s):  
High Speed ◽  
Wear Behavior ◽  
Energy Levels ◽  
Thermal Spraying ◽  
High Energy ◽  
Coated Steel ◽  
High Speed Trains ◽  
To Come ◽  
Tribological Characterization

Abstract Optimization of constitutive friction materials of braking devices for high speed trains is endlessly on delicate increase by reason of the large energy levels to dissipate, and the lightening more and more required by generations to come. Low thermal diffusivity materials such as coated steel discs in one of the research themes in this field. Proposed study is relative to tribological characterization of the wear behavior of stellite coatings, based on cobalt or nickel alloys against aluminum titanate pad. This one has ever been tested and prooved good behavior against cermet coated steel discs. Stellite coating performances are evaluated in term of friction coefficient, contact temperature and wear in comparison with this type of disc.

Performance of a Matrix Type High Speed Steel after Deep Cryogenic and Low Tempering Temperature

2021 ◽  
Vol 1016 ◽  
pp. 1423-1429
Author(s):  
Kaweewat Worasaen ◽  
Andreas Stark ◽  
Karuna Tuchinda ◽  
Piyada Suwanpinij
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
Cryogenic Treatment ◽  
High Speed Steel ◽  
High Energy ◽  
Single Step ◽  
Deep Cryogenic Treatment ◽  
Tempering Temperature ◽  
Matrix Type ◽  
Bcc Structure

A matrix type high speed steel YXR3 designed for a combination of wear resistance and toughness is investigated for its mechanical properties after hardening by deep cryogenic treatment follow by tempering. The deep cryogenic quenching carried out at -200 °C for 36 hours and the single step tempering results in an obvious improvement in wear resistance while balancing the toughness, comparing with the conventional quenching followed by a double tempering treatment. The quantitative image analysis reveals little difference in the MC carbide size distribution between tempering at different temperatures. The synchrotron high energy XRD confirms the MC type carbide with some evolution in its orientation together with tempered martensite approaching the BCC structure at higher temperatures. In contrary to the conventional quenching and tempering, the lowest tempering temperature at 200 °C yields a moderate drop in hardness with increase in surface toughness proportionally while exhibiting exceptional wear resistance. Such thermal cycle can be recommended for the industry both for the practicality and improved tool life.

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