Structural changes in the surface layers of sealing material S-137 in high-speed dry friction

1974 ◽  
Vol 7 (6) ◽  
pp. 660-663
Author(s):  
N. L. Golego ◽  
M. E. Belitskii ◽  
A. D. Gaidarenko ◽  
V. A. Lyashko
Keyword(s):  
Dry Friction ◽  
High Speed ◽  
Structural Changes ◽  
Surface Layers ◽  
Sealing Material

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

Mössbauer study of surface layers of high-speed steel after laser treatment

1992 ◽  
Vol 69 (1-4) ◽  
pp. 589-592 ◽  
Author(s):  
R. Valiev ◽  
V. Bochkov ◽  
Sh. Bashkirov ◽  
E. Romanov ◽  
V. Chistjakov
Keyword(s):  
Laser Treatment ◽  
High Speed ◽  
High Speed Steel ◽  
Surface Layers ◽  
Mössbauer Study

Estimation of the Heat Stability of Hardened Cr-V Cast Irons

2016 ◽  
Vol 870 ◽  
pp. 558-563
Author(s):  
Yu.D. Koryagin ◽  
V.L. Il'ichev
Keyword(s):  
High Speed ◽  
Structural Changes ◽  
High Speed Steel ◽  
Heat Stability ◽  
Maximum Hardness ◽  
Cast Irons ◽  
Wear Resistant ◽  
Secondary Hardness ◽  
Double Tempering ◽  
Structure Properties

The paper describes the structure, properties and heat stability of white cast irons containing 2.5 – 3.0 %C, 14 and 20 %Cr, 3 %V after the secondary hardness treatment (quenching from 1150 °C and double tempering at 560 °C). It is shown that after the secondary hardness treatment M23C6 carbides appear along with the M7C3 phase. Heat stability of the alloys is estimated according to GOST 19265-73 standard. The effect of the temperature and duration of holding at 520–620 °C on structural changes and softening of secondary hardness treated cast irons is considered in comparison with high-speed steel and cast irons of the same composition quenched for the maximum hardness (from 1050 °C). The processes occurring at higher temperatures and long holdings that are responsible for softening of secondary hardness treated cast irons are studied. It is shown that the alloys under consideration after the secondary hardness treatment achieve the hardness of HRC 60 and more, and are able of pertaining it when heated up to 540 °C for 20 hours. This allows using these alloys as wear-resistant materials in the said temperature range.

scholarly journals Phase-transformation-induced lubrication of earthquake sliding

2017 ◽  
Vol 375 (2103) ◽  
pp. 20160008 ◽  
Author(s):  
Harry W. Green
Keyword(s):  
Phase Transformation ◽  
Dry Friction ◽  
High Speed ◽  
Frictional Resistance ◽  
Low Pressure ◽  
Self Healing ◽  
Strength Recovery ◽  
Endothermic Reactions ◽  
Shear Heating ◽  
Fast Motion

Frictional failure is not possible at depth in Earth, hence earthquakes deeper than 30–50 km cannot initiate by overcoming dry friction. Moreover, the frequency distribution of earthquakes with depth is bimodal, suggesting another change of mechanism at about 350 km. Here I suggest that the change at 30–50 km is from overcoming dry friction to reduction of effective stress by dehydration embrittlement and that the change at 350 km is due to desiccation of slabs and initiation by phase-transformation-induced faulting. High-speed friction experiments at low pressure indicate that exceeding dry friction provokes shear heating that leads to endothermic reactions and pronounced weakening. Higher-pressure studies show nanocrystalline gouge accompanying dehydration and the highest pressure experiments initiate by exothermic polymorphic phase transformation. Here I discuss the characteristic nanostructures of experiments on high-speed friction and high-pressure faulting and show that all simulated earthquake systems yield very weak transformation-induced lubrication, most commonly nanometric gouge or melt. I also show that phase-transformation-induced faulting of olivine to spinel can propagate into material previously transformed to spinel, apparently by triggering melting analogous to high-speed friction studies at low pressure. These experiments taken as a whole suggest that earthquakes at all depths slide at low frictional resistance by a self-healing pulse mechanism with rapid strength recovery. This article is part of the themed issue ‘Faulting, friction and weakening: from slow to fast motion’.

scholarly journals Strategic Directions of Pedagogical Personnel Training for the System of Continuing Vocational Education

2019 ◽  
Vol 21 (6) ◽  
pp. 93-121 ◽  
Author(s):  
E. F. Zeer ◽  
V. S. Tretyakova ◽  
V. I. Miroshnichenko
Keyword(s):  
Vocational Education ◽  
Research Methods ◽  
Vocational Training ◽  
High Speed ◽  
Structural Changes ◽  
Research Work ◽  
Practical Significance ◽  
Inductive Method ◽  
Highly Qualified ◽  
Speed Training

. Introduction. Transition to a post-industrial socio-economic structure and information society caused education crisis, which is common for world space. Dynamic development of high technologies and rapid obsolescence of knowledge significantly reduced life cycle of professions and caused deep structural changes in the sphere of employment. The need of economics for workers with qualitatively new qualification characteristics - a flexible person with meta-professional competencies, capable to solve complex professional problems and ready for innovative activity not just for today, but with the future in mind - has necessitated a significant updating of the system of vocational training and its reorganisation facilitating the implementation of a formula “lifelong learning”. The solution of problems of education begins with qualitative training of teachers, since the qualities of future professionals - graduates of the educational organisation, primarily depend on the level of teachers’ competencies.The aim of the present article is to determine the strategic directions of innovative development of vocational education and preparation of highly qualified pedagogical personnel.Methodology and research methods. The hypothetico-inductive method, theoretic-methodological analysis and synthesis of the content of scientific literature were the major research methods. The research work was carried out on the basis of the principle of convergence, which determines cross-disciplinary and supra-professional communications, acts as a factor of design and a statement in professiology of a new phenomenon - transprofessionalism. The authors described the concept of transprofessionalism through the process- and project-based approaches.Results and scientific novelty. The developmental trends and directions of vocational education are considered. The principal defining factor of vocational education is close integration of all its processes and subsystems (prevocational training - secondary vocational education - higher education institutions - postgraduate training), which integrity is provided by the continuing and advanced education. The concept of transprofessionalism and convergence in multidisciplinary training of specialists is proved. The innovative educational programmes based on this concept are characterised. The logical-semantic model of a modern specialist is designed. This model can form an empirical basis to design vocational education platform, which integrates socio-humanistic, natural-science disciplines and related innovative technologies for teachers’ training in the system of continuing vocational education. Strategic directions for realisation of such preparation are formulated: transprofessionalism, cooperation / collaboration, advanced and “high-speed” training, digital transformation.Practical significance. The research materials can be useful for specialists in the field of vocational education, heads of the educational organisations in order to develop and make managerial decisions and to effectively organise the process of vocational training of pedagogical personnel.

Effect of diamond dressing on the state of the surface layers of high-speed steel cutting tools

1972 ◽  
Vol 4 (6) ◽  
pp. 516-518
Author(s):  
V. Ya. Bulanov ◽  
A. P. Shevel ◽  
P. A. Yudkovskii
Keyword(s):  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
The State ◽  
Surface Layers ◽  
Steel Cutting

An experimental investigation of the effects of compressibility on a turbulent reacting mixing layer

1998 ◽  
Vol 356 ◽  
pp. 25-64 ◽  
Author(s):  
M. F. MILLER ◽  
C. T. BOWMAN ◽  
M. G. MUNGAL
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Structural Changes ◽  
Density Ratio ◽  
Mixing Layer ◽  
Mixing Layers ◽  
Unexpected Result ◽  
Entrainment Ratio ◽  
Plan View ◽  
Compressible Mixing Layer

Experiments were conducted to investigate the effect of compressibility on turbulent reacting mixing layers with moderate heat release. Side- and plan-view visualizations of the reacting mixing layers, which were formed between a high-speed high-temperature vitiated-air stream and a low-speed ambient-temperature hydrogen stream, were obtained using a combined OH/acetone planar laser-induced fluorescence imaging technique. The instantaneous images of OH provide two-dimensional maps of the regions of combustion, and similar images of acetone, which was seeded into the fuel stream, provide maps of the regions of unburned fuel. Two low-compressibility (Mc=0.32, 0.35) reacting mixing layers with differing density ratios and one high-compressibility (Mc=0.70) reacting mixing layer were studied. Higher average acetone signals were measured in the compressible mixing layer than in its low-compressibility counterpart (i.e. same density ratio), indicating a lower entrainment ratio. Additionally, the compressible mixing layer had slightly wider regions of OH and 50% higher OH signals, which was an unexpected result since lowering the entrainment ratio had the opposite effect at low compressibilities. The large-scale structural changes induced by compressibility are believed to be primarily responsible for the difference in the behaviour of the high- and low-compressibility reacting mixing layers. It is proposed that the coexistence of broad regions of OH and high acetone signals is a manifestation of a more biased distribution of mixture compositions in the compressible mixing layer. Other mechanisms through which compressibility can affect the combustion are discussed.

Tribological Characteristic of Tool Steel Surface Layer Alloyed Using Laser

2020 ◽  
Vol 308 ◽  
pp. 110-118
Author(s):  
Mirosław Bonek ◽  
Eva Tillová
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Structural Changes ◽  
Dendritic Structure ◽  
High Speed Steel ◽  
Beam Power ◽  
Ceramic Phase ◽  
Structural Mechanism ◽  
Conventional Heat Treatment ◽  
The Impact

The article presents the results of research on the impact of laser surface treatment on selected steel properties. The laser treatment consisted of remelting and alloying high speed steel using hard ceramic phase powders. A high-power diode laser was used in the experiment to examine the effect of parameters such as beam power and powder type on the structure and properties of the surface layer. A structural mechanism was observed consisting in obtaining, after laser processing, a super fine crystalline structure and a dendritic structure at the remelting zone. Structural changes have been found to be associated with improved properties such as hardness, microhardness and wear resistance. Steel treated with conventional heat treatment was used as a comparative material.

Effects of Electrolyte Plasma Carbonitriding on Tribological Properties of High Speed Steel

2013 ◽  
Vol 712-715 ◽  
pp. 7-11 ◽  
Author(s):  
Mazhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Michael Sсheffler
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
High Speed ◽  
High Speed Steel ◽  
Scratch Test ◽  
Abrasive Wear Resistance ◽  
R6m5 Steel ◽  
Surface Layers ◽  
Test Conditions ◽  
Modified Layer

This paper presents research of influence electrolyte plasma carbonitriding on tribological properties of R6M5 high-speed steel. Shows perspectiveness of carbonitriding high-speed steels in electrolyte plasma. The results of research demonstrated increasing wear-resistance of R6M5 steel after carbonitriding in electrolyte plasma. Under the same test conditions by the method of scratch-test have been determined that the depth of the scar of a modified layer has become less in comparison with the original sample, which indicates a significant increase of wear-resistance and hardness of the surface carbonitriding layer R6М5 steel. It was set that after electrolytic-plasma carbonitriding abrasive wear-resistance of the surface layers of R6M5 steel is increased by 25%. Introduction

Sign in / Sign up

Export Citation Format

Share Document