The asymmetric (e, 2e) collisions at intermediate and high impact energy: success and limits of first-order models

1988 ◽  
Vol 21 (11) ◽  
pp. 2145-2157 ◽  
Author(s):  
A Lahmam-Bennani ◽  
L Avaldi ◽  
E Fainelli ◽  
G Stefani
Keyword(s):  
Impact Energy ◽  
High Impact ◽  
High Impact Energy ◽  
First Order

Wear behaviors of WC and TiC on co matrix composites under three-body impact abrasive wear condition

2019 ◽  
Vol 71 (7) ◽  
pp. 893-900 ◽  
Author(s):  
Lei Dong ◽  
Xiaoyu Zhang ◽  
Kun Liu ◽  
Xiaojun Liu ◽  
Ruiming Shi ◽  
...  
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Impact Energy ◽  
Wear Behavior ◽  
High Impact ◽  
Impact Wear ◽  
High Impact Energy ◽  
Content Type ◽  
Three Body ◽  
The Impact

Purpose The purpose of this paper is to investigate the tribological properties of the WC/TiC-Co substrate under different loading conditions under three impact abrasive wear conditions. Design/methodology/approach The three body collisional wear behavior of Co alloy with WC and TiC at three impact energy was studied from 1 to 3 J. Meanwhile, the microstructure, hardness, phase transformation and wear behavior of these specimens were investigated by scanning electron microscopy, Rockwell hardness (HRV), EDS and impact wear tester. The resulting wear rate was quantified by electronic balance measurements under different pressures. Findings The specific wear rate increases with the increase of the nonlinearity of the impact energy and the increase in the content of WC or TiC. The effect of TiC on wear rate is greater than that of WC, but the hardness is smaller. The wear characteristics of the samples are mainly characterized by three kinds of behavior, such as cutting wear, abrasive wear and strain fatigue wear. The WC-Co with fewer TiC samples suffered heavier abrasive wear than the more TiC samples under both low and high impact energy and underwent fewer strain fatigue wears under high impact energy. Originality/value The experimental results show that the wear resistance of the Co alloy is improved effectively and the excellent impact wear performance is achieved. The results can be used in cutting tools such as coal mine cutting machines or other fields.

Optimization of Heat Treatment Parameters of Mo-Free High-Cr Cast Iron Mill Balls

2007 ◽  
Vol 26-28 ◽  
pp. 913-916 ◽  
Author(s):  
Sang Mok Lee ◽  
Bong Hwan Kim ◽  
Je Sik Shin ◽  
B.M. Moon
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Impact Energy ◽  
Treatment Condition ◽  
Heat Treatment Condition ◽  
High Impact ◽  
High Impact Energy ◽  
Surface Method ◽  
Designs Of Experiments ◽  
Proper Balance

A Mo-free high-Cr cast iron with superior impact-wear resistance was tried to develop for mill balls by alloy design and subsequent heat treatment. The Cr/C ratio was varied up to 7.7 in order to minimize and eventually eliminate Mo addition, still ensuring hardenability. For the proper balance between abrasion resistance and toughness, the combined effects of each heat treatment parameters on the mechanical properties were systematically investigated using Taguchi method and response surface method (RSM), well recognized as powerful tools of the designs of experiments (DOE). It was found that hardness and impact energy were mainly affected by tempering and destabilization conditions, respectively. It is noted that high impact energy of 5.2 J/cm2 was obtained without deteriorating hardness (54 HRc) during the verification experiments under the heat treatment condition optimized by the DOE analyses.

scholarly journals A Control Method of High Impact Energy and Cosimulation in Powder High-Velocity Compaction

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Dongdong You ◽  
Dehui Liu ◽  
Hangjian Guan ◽  
Qingyun Huang ◽  
Zhiyu Xiao ◽  
...  
Keyword(s):  
Impact Energy ◽  
High Velocity ◽  
Mechanical Energy ◽  
High Impact ◽  
Experimental Results ◽  
Hydraulic Control ◽  
Green Density ◽  
High Impact Energy ◽  
High Velocity Compaction ◽  
The Impact

To enhance the impact energy of powder high-velocity compaction (HVC) and thus improve the green density and mechanical properties of the resulting compacts, a mechanical energy storage method using combination disc springs is proposed. The high impact energy is achieved by modifying existing equipment, and the hydraulic control system is developed to implement the automatic control of the energy produced from the disc springs. An interdisciplinary cosimulation platform is established using the ADAMS, AMESim, and LabVIEW software packages to perform the interactive control of the simulation process and the real-time feedback of the simulation results. A mechanical-hydraulic cosimulation of the energy control virtual prototype of the testing machine is conducted using this platform. The influence of the impact energy on the green density is studied according to the HVC experimental results of the iron-based powders, and then, the green compact with the higher relative density is produced. The experimental results indicate that the energy enhancement method using the combination disc springs is reasonable and that the hydraulic control scheme is reliable.

The Role of the Atmosphere on Boron-Activated Sintering of Ferrous Powder Compacts

2018 ◽  
Vol 18 (1) ◽  
pp. 6-20 ◽  
Author(s):  
V. Vassileva ◽  
H. Danninger ◽  
S. Strobl ◽  
Ch. Gierl-Mayer ◽  
R. de Oro Calderon ◽  
...  
Keyword(s):  
Impact Energy ◽  
Hydrogen Atmosphere ◽  
High Impact ◽  
High Impact Energy ◽  
Energy Data ◽  
Transgranular Cleavage ◽  
Powder Compacts ◽  
The Impact ◽  
Considerable Depth

Abstract Boron has been known to activate densification during sintering of ferrous powder compacts, though with risk of embrittlement. In the present study, specimens Fe-B and Fe-C-B prepared from standard atomized iron powder with addition of ferroboron Fe-21%B were sintered in different atmospheres, and the resulting microstructures and properties were studied. It showed that the activating effect of boron is observed during sintering in argon and in hydrogen while sintering in N2 containing atmospheres results in rapid deactivation of boron, through formation of stable BN. In hydrogen atmosphere, surface deboronizing was observed to considerable depth. Ar is chemically inert, but Ar trapped inside closed pores tends to inhibit further densification. The impact energy data indicated that the embrittling effect of boron is enhanced significantly by presence of carbon. In the fracture surfaces, transgranular cleavage fracture can be observed both at very low and high impact energy values.

Subsurface Microstructure Evolution of Hadfield Steel under High Impact Energy

2005 ◽  
Vol 475-479 ◽  
pp. 117-120 ◽  
Author(s):  
Yun Hua Xu ◽  
Liang Fang ◽  
Qihong Cen ◽  
Jin Hua Zhu
Keyword(s):  
Microstructure Evolution ◽  
Impact Energy ◽  
Amorphous Solid ◽  
High Energy ◽  
High Impact ◽  
Hadfield Steel ◽  
High Impact Energy ◽  
Energy Impact ◽  
Austenite Grains ◽  
Subsurface Microstructure

It has been well known that Hadfield steel behaviors excellent wear resistance under high impact energy. Up to now there exist many theories to explain the wear mechanism of Hadfield steel. In this research subsurface microstructure evolution process of Hadfield steel was investigated after high energy impact experiments. It was shown from high resolution electron microscope (HRTEM) examination of subsurface microstructure that nanocrystallized austenite grains have been formed in the procedure of the reaction and rearrangement of high density dislocations under the heavy plastic deformation, sub-grains as a transitional structure and, finally, the formation of nano austenite grains. On the other side, the interactions of twins and stack faults or dislocations and stack faults make austenite crystals transform to amorphous solid. With increasing impact cycles the sizes of nano-grains were decreased and the amorphous volumes were increased further. A large amount of nano-sized grains embedded in bulk amorphous matrix were fully developed, which will dominate the wear of the steel. In the subsurface no martensitic transformation was observed.

Self-woven nanofibrillar PEDOT mats for impact-resistant supercapacitors

2019 ◽  
Vol 3 (5) ◽  
pp. 1154-1162 ◽  
Author(s):  
Hongmin Wang ◽  
Luciano M. Santino ◽  
Micah Rubin ◽  
Yifan Diao ◽  
Yang Lu ◽  
...  
Keyword(s):  
Impact Energy ◽  
High Impact ◽  
High Impact Energy ◽  
Flexible Supercapacitors

Horizontally directed nanofibrillar PEDOT mats bearing high impact energy densities are fabricated as electrodes for impact-resistant flexible supercapacitors.

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