Mechanisms of structural-phase transformations during crystallization of a solder melt

Problem statement. An important requirement is quality assurance of joining materials with minimal overheating of materials, lowering the soldering temperature and suppressing the interaction of the solder with the materials to be soldered. The heating of the solder and the holder should be as uniform as possible and with a minimum temperature difference along the depth. One solution may be to develop more efficient solders and fluxes, adapted to the high heating rates that are typical when using high frequency currents Purpose. Thus, the problems of uniform heating of parts during brazing are relevant. This is necessary for optimal distribution of the electromagnetic field in the contact area Methodology. The effect of the heating rate was investigated. The composition of the flux and solders on the microstructure of the solders and the brazed seam was performed on the joints of HV510 (DIN), HS345 (DIN), HG30 (DIN) hardmetal plates with steel holders made of 5135 (USA) steel with a section of 25×20. Results. The research of the processes showed that during the contact interaction of low-melting and refractory components of the solders, when the tool was soldered, the solder is formed in the seam and proceeds through several stages. Practical value. Contact interaction of copper-zinc melts with iron particles does not lead to complete dissolution of iron particles. This is explained to the low values of the solubility of iron in copper-zinc melts despite the fact that resistive heat release occurs in the particles. Such iron particles (iron-based alloy) act as a dispersed phase in the structure of the composite material.

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Mechanisms of structural-phase transformations during crystallization of solder melt under conditions of magnetic-dynamic influences for carbide tools

Bulletin of the National Technical University «KhPI» Series New solutions in modern technologies ◽

10.20998/2413-4295.2021.03.06 ◽

2021 ◽

pp. 40-47

Author(s):

Anatoliy Kuzey ◽

Vladimir Lebedev ◽

Pavel Tsykunov ◽

Andrey Slipchuk

Keyword(s):

Contact Interaction ◽

Structural Phase ◽

High Strength ◽

Grain Structure ◽

Hard Alloys ◽

Soldering Temperature ◽

Hardening Mechanism ◽

Soldering Process ◽

Magnetic Dynamic ◽

Copper Zinc

The processes of melt formation were studied by methods of optical and electron scanning microscopy. These processes occur during induction brazing of a hard alloy to a steel holder and contact interaction of low-melting (copper-zinc system alloy) and refractory (iron-nickel) components of the solders. It is shown that the effect of a thermal and magnetic-dynamic high-frequency electromagnetic field on the components of the composite solder is how a high-strength solder joint is formed. The structure is forming by disperse hardening mechanism. The research of the contact interaction process for low-melting and high-melting components of solders during the soldering process of the tool showed that the formation of solder in brazed seams occurs through a number of stages and this does not lead to the formation of microstructures that are characteristic of alloys based on copper-iron-phosphorus, copper-zinc-nickel and copper-zinc-iron. Thus, the use of composite solders can reduce the soldering temperature by 40-50 K and increase the concentration of alloying species in the solder and change its structure. These advantages of composite solders reduce the thermal impact on contact materials, increase the strength of the weld and allow you to control the thickness of the brazed weld, and this is important when soldering hard alloys of WC-TiC (TaC) systems. High initial dissolution rates of nickel particles in the copper-zinc melt and the solubility of copper, zinc in nickel lead to the formation in the melt of quasi-liquid particles of the nickel alloy. When the melt is cooled, particles other than the surrounding alloy composition are formed. They are morphologically related to the grain structure of the solder. The formed alloy (solder) has the structure of a composite material in which the metal particles are enriched in nickel, and have the role of a reinforcing element.

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The features of structural-phase transformations in the 12Kh18N10T stainless steel subjected to high-frequency hydrodynamic effects under high pressure

Diagnostics Resource and Mechanics of materials and structures ◽

10.17804/2410-9908.2017.4.052-060 ◽

2017 ◽

pp. 52-60

Author(s):

V. G. Pushin ◽

◽

E. Yu. Muryshev ◽

E. S. Belosludtseva ◽

N. N. Kuranova ◽

...

Keyword(s):

High Pressure ◽

Stainless Steel ◽

Phase Transformations ◽

High Frequency ◽

Structural Phase ◽

Hydrodynamic Effects ◽

Structural Phase Transformations

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STRUCTURAL PHASE TRANSFORMATIONS IN THE INDIUM-RICH SOLID SOLUTIONS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1982415 ◽

1982 ◽

Vol 43 (C4) ◽

pp. C4-145-C4-150 ◽

Cited By ~ 5

Author(s):

Y. Koyama ◽

O. Nittono

Keyword(s):

Phase Transformations ◽

Solid Solutions ◽

Structural Phase ◽

Structural Phase Transformations

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Structure and properties of gas-dynamic coatings and evaluation of their use in sliding friction pairs

10.36652/1813-1336-2020-16-6-260-266 ◽

2020 ◽

pp. 260-266

Author(s):

V.E. Arkhipov ◽

T.I. Murav’eva ◽

M.S. Pugachev ◽

O.O. Shcherbakova

Keyword(s):

Aluminum Oxide ◽

Sliding Friction ◽

Metal Layer ◽

Structural Phase ◽

Mechanical Mixture ◽

Structural Factors ◽

Coating Structure ◽

Corundum Structure ◽

Deposited Metal ◽

Copper Zinc

The problems of changes in the coating structure depending on the composition of the sprayed mechanical mixture using copper particles and mixture of copper and zinc particles (" brass") and the effect of structural factors on the tribological properties of the deposited metal layer are considered. The results of X-ray structural, phase, chemical and durometric analyzes, as well as tribological testing of coatings are presented. It is found that structure with hardness of ≈102.7 HV is formed in the coating from mechanical mixture of particles of copper and aluminum oxide (corundum). Numerous pores are observed in the structure of the deposited metal layer, the main size of which does not exceed 2 μm. In the coating from mechanical mixture of particles copper, zinc and aluminum oxide (corundum), structure is formed based on copper with hardness of ≈106.5 HV, zinc — ≈49.7 HV, intermetallic compounds (γ- and ε-phases) — ≈168.7 HV, the mass fraction of which is 62.0, 7.9 and 24.2 %, respectively. Both coatings can be used in sliding friction pairs.

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