Investigation of intercrystallite corrosion in some surfacing hard alloys

1976 ◽  
Vol 12 (6) ◽  
pp. 575-575
Author(s):  
R. A. Sataev ◽  
S. P. Levitskii
Keyword(s):  
Hard Alloys ◽  
Intercrystallite Corrosion

Materials for bullet core

2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Low Alloy Steels ◽  
Hard Alloys ◽  
Small Arms ◽  
Alloy Steels ◽  
Materials Used ◽  
Basic Ideas ◽  
New Generation ◽  
Natural Composite

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.

A method for evaluating the edge strength of soil-cutting parts of forestry machines

2020 ◽  
Vol 67 (1) ◽  
pp. 111-115
Author(s):  
Sergey A. Voynash ◽  
Viktoriya A. Sokolova ◽  
Viktor I. Kretinin ◽  
Viktor A. Markov ◽  
Elena A. Alekseeva Alekseeva ◽  
...  
Keyword(s):  
Fatigue Failure ◽  
Research Purpose ◽  
Solid Inclusion ◽  
Hard Alloys ◽  
Blade Edge ◽  
Solid Soil ◽  
Soil Cutting ◽  
Cyclic Impact ◽  
Working Bodies ◽  
Reinforcing Layer

One of the main factors that determine the resistance of blade working bodies against damage under dynamic loads is their resistance to plastic crumpling, brittle or fatigue failure. Hard alloys that strengthen the blades of tillage parts are more brittle materials than steel, so the blunting of their edges is caused by the formation of cracks, their gradual growth or microchipping, even from a possible single impact of a solid inclusion in the soil. In addition to the usual brittle fracture of hard alloys, fatigue failure occurs under cyclic impact conditions. (Research purpose) The research purpose is in identifying the pattern of destruction of the blade edge of soil-cutting parts of forestry machines and theoretically justifying the algorithm for assessing the strength to determine the rational thickness of the wear-resistant coating during hardening. (Materials and methods) The article presents the main regularities of the influence of material properties and geometric parameters of the blade on the radius of rounding. (Results and discussion) The process of breaking the edge of the blade of hardened working bodies of forestry machines has been studied. The claim that the blunting of the blades is mainly due to its destruction and not to wear has been proved. The article presents a method for evaluating the strength of bimetallic blades of soil-cutting parts of forestry machines. It was found that the blunting of the blade occurs as a result of edge destruction in the process of multiple impacts of solid soil inclusions along the edge of the blade. (Conclusions) The article shows that the destruction of the edge of the blade leads to blunting of soil-cutting parts, which affects their performance. It was found that the sharpness of a self-sharpening hardened blade is determined by the thickness of the reinforcing layer and its ability to resist destruction under impact.

Tribotechnical characteristics of hard alloys in sliding friction units

2020 ◽  
pp. 87-97
Author(s):  
K. D. Khromushkin ◽  
B. G. Ushakov ◽  
A. V. Kochergin ◽  
R. A. Suleev ◽  
O. N. Parmenova
Keyword(s):  
Experimental Data ◽  
Sliding Friction ◽  
Heating Temperature ◽  
Hard Alloys ◽  
Friction Units ◽  
Wear And Friction ◽  
Friction Path ◽  
Friction Parameters ◽  
Tribotechnical Characteristics ◽  
Temperature Surface

The paper presents experimental data on the study of the friction parameters of hard alloys in sliding friction units, including the heating temperature, surface roughness, wear and friction coefficient, depending on the duration of the test and the friction path.

scholarly journals Ultralow-cobalt hard alloys obtained by spark plasma sintering

2021 ◽  
Vol 1014 (1) ◽  
pp. 012020
Author(s):  
E A Lantsev ◽  
V N Chuvil’deev ◽  
A V Nokhrin ◽  
M S Boldin ◽  
N V Malekhonova ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Hard Alloys ◽  
Plasma Sintering ◽  
Spark Plasma

Preparation of WC-TiC-Ni3Al-CaF2 functionally graded self-lubricating tool material by microwave sintering and its cutting performance

2020 ◽  
Vol 39 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Siwen Tang ◽  
Rui Wang ◽  
Pengfei Liu ◽  
Qiulin Niu ◽  
Guoqing Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Microwave Heating ◽  
Cutting Performance ◽  
Conventional Heating ◽  
Hard Alloys ◽  
Dry Cutting ◽  
Temperature Oxidation ◽  
Lubricating Material ◽  
Heating Technology

AbstractWith the concern of the environment, green dry cutting technology is getting more and more attention and self-lubricating tool technology plays an important role in dry cutting. Due to the demand for high temperature performance of tools during dry cutting process, cemented carbide with Ni3Al as the binder phase has received extensive attention due to its excellent high temperature strength and high temperature oxidation resistance. In this paper, WC-TiC-Ni3Al-CaF2 graded self-lubricating material and tools were prepared by microwave heating method, and its microstructure, mechanical properties and cutting performance were studied. Results show that gradient self-lubricating material can be quickly prepared by microwave heating technology, and the strength is equivalent to that of conventional heating technology. CaF2 not only plays a role in self-lubrication, but also refines the grain of the material. A reasonable gradient design can improve the mechanical properties of the material. When the gradient distribution exponent is n1 = 2, the material has high mechanical properties. Cutting experiments show that the WC-TiC-Ni3Al-CaF2 functional gradient self-lubricating tool has better cutting performance than the homogeneous WC-TiC-Ni3Al hard alloys.

scholarly journals A Study of the Impact of Graphite on the Kinetics of SPS in Nano- and Submicron WC-10%Co Powder Compositions

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 331-363
Author(s):  
Eugeniy Lantcev ◽  
Aleksey Nokhrin ◽  
Nataliya Malekhonova ◽  
Maksim Boldin ◽  
Vladimir Chuvil'deev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Continuous Heating ◽  
Diffusion Creep ◽  
Hard Alloys ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact ◽  
Kinetics Of

This study investigates the impact of carbon on the kinetics of the spark plasma sintering (SPS) of nano- and submicron powders WC-10wt.%Co. Carbon, in the form of graphite, was introduced into powders by mixing. The activation energy of solid-phase sintering was determined for the conditions of isothermal and continuous heating. It has been demonstrated that increasing the carbon content leads to a decrease in the fraction of η-phase particles and a shift of the shrinkage curve towards lower heating temperatures. It has been established that increasing the graphite content in nano- and submicron powders has no significant effect on the SPS activation energy for “mid-range” heating temperatures, QS(I). The value of QS(I) is close to the activation energy of grain-boundary diffusion in cobalt. It has been demonstrated that increasing the content of graphite leads to a significant decrease in the SPS activation energy, QS(II), for “higher-range” heating temperatures due to lower concentration of tungsten atoms in cobalt-based γ-phase. It has been established that the sintering kinetics of fine-grained WC-Co hard alloys is limited by the intensity of diffusion creep of cobalt (Coble creep).

scholarly journals Color-Metallographic Characterization of Alloyed White Cast Irons Ni-Hard Type

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 728
Author(s):  
Milagrosa González Fernández de Castro ◽  
Yolanda Martín Álvarez ◽  
Juan José Moreno-Labella ◽  
Miguel Panizo-Laiz ◽  
Benito del Río
Keyword(s):  
Impact Resistance ◽  
Solidification Structure ◽  
Hard Alloys ◽  
Metallic Materials ◽  
Low Carbon ◽  
Cast Irons ◽  
The Family ◽  
Color Metallography ◽  
Hard Type

The Ni-hard alloys white-cast irons are generally used for high wear work. Among them, those with better impact resistance because of its low carbon content compared to the rest of the family, are studied in this paper. One experimental technique of characterizing the metallic materials is the microstructural study. Several metallographic attacks intended to reveal qualitatively each microconstituent that forms the alloy, as well as the segregation and solidification structure of casting, are studied in this article. The use of color metallography is fundamental in this case to distinguish clearly the microconstituents. The main objective of this paper is to propose a series of attacks that identify each one of the microconstituents present in the alloy that has not been reported up to date.

Effects of technological features on the structure and properties of tungsten-free hard alloys

1992 ◽  
Vol 28 (5) ◽  
pp. 463-465
Author(s):  
L. G. Bodrova ◽  
G. M. Kramar ◽  
S. A. Artem'yuk
Keyword(s):  
Hard Alloys ◽  
Structure And Properties
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