Automated dihedral angle measurement in liquid phase sintered alloys

2004 ◽  
Vol 95 (1) ◽  
pp. 3-7 ◽  
Author(s):  
P. Chhillar ◽  
S. Sangal ◽  
A. Upadhyaya
Keyword(s):  
Liquid Phase ◽  
Dihedral Angle ◽  
Angle Measurement ◽  
Sintered Alloys

Interaction of Components of Co-Sn and Co-Sn-Cu Powder Materials in Liquid Phase Sintering

2019 ◽  
Vol 943 ◽  
pp. 113-118
Author(s):  
Evgeniy Georgiyevich Sokolov ◽  
Alexander Vitalyevich Ozolin ◽  
Lev Ivanovich Svistun ◽  
Svetlana Alexandrovna Arefieva
Keyword(s):  
Liquid Phase ◽  
Solid Phase ◽  
Steel Substrate ◽  
Liquid Phase Sintering ◽  
Powder Materials ◽  
Cu Alloys ◽  
Initial Stage ◽  
Interaction Of Components ◽  
Sintered Alloys ◽  
Liquid Tin

The interaction of components and structure formation were studied in liquid phase sintering of Co-Sn and Co-Sn-Cu powder materials. The powders of commercially pure metals were mixed with an organic binder and applied on the steel substrate. Sintering was performed under vacuum at temperatures of 820 and 1100 °C. The structure of sintered alloys was investigated by X-ray diffractometry and electron probe microanalysis, and microhardness (HV0.01) of the structural components was measured. It has been found that the nature of interaction of the liquid tin with the solid phase at the initial stage of sintering affects the formation of structure and porosity of Co-Sn and Co-Sn-Cu alloys considerably. In Co-Sn alloys, diffusion of tin into cobalt particles leads to the formation of intermetallic compounds, which hinders spreading of the liquid phase. This results in a porous defect structure formed in Co-Sn alloys. In Co-Sn-Cu alloys, at the initial stage of sintering the liquid phase enriched with copper is formed that wets the cobalt particles and contributes to their regrouping. As a result of this, materials with minor porosity are formed.

scholarly journals A stereoscopic method for dihedral angle measurement

2005 ◽  
Vol 40 (12) ◽  
pp. 3121-3127 ◽  
Author(s):  
L. Felberbaum ◽  
A. Rossoll ◽  
A. Mortensen
Keyword(s):  
Dihedral Angle ◽  
Angle Measurement

Effect of silicon on the properties of sintered alloys of (Al – Si) – Sn system

2021 ◽  
Vol 5 ◽  
pp. 37-48
Author(s):  
N. M. Rusin ◽  
◽  
A. L. Skorentsev ◽  
Keyword(s):  
Wear Resistance ◽  
Liquid Phase ◽  
Dry Friction ◽  
Structural Features ◽  
Liquid Phase Sintering ◽  
Favorable Effect ◽  
Sintered Compact ◽  
Friction Forces ◽  
Aluminum Powders ◽  
Sintered Alloys

Structural features of composites of the (Al – xSi) – 40Sn system prepared by liquid-phase sintering of mixtures of tin powder of PO 2 grade with powders of Al – Si alloys of hypoeutectic, eutectic, and hypereutectic composition were studied in this work. Samples were cut from the prepared materials for compression test and dry friction test against steel according to the “pin-on-disk” scheme. It was established that the main structural elements of the sintered composites are determined by the nature of interaction of solid silumin particles and liquid tin. This is due to the fact that tin not only spreads over the volume of the sintered compact, but also activates the processes of recrystallization of aluminum powders due to dissolution of their atoms in the liquid phase with subsequent deposition on the large particles surface. The dissolution weakens the skeleton of aluminum powders, and they are able to regroup into a denser configuration under the action of capillary forces. It was found that silicon inhibits the shrinkage of the compacts during the liquid-phase sintering. Therefore, to improve the mechanical properties of the sintered composites, they should be subjected to additional densification in order to eliminate their residual porosity, which simultaneously contributes to a significant increase in their wear resistance under dry friction. The study of the wear features of the (Al – хSi) – 40Sn composites was carried out. It was found that silicon particles located in the tin interlayers hinder the relative shear of the neighboring matrix grains and increase the thickness of the surface layer involved in deformation by friction forces. This fact has a favorable effect on the wear resistance of the investigated sintered composites under dry friction process. The (Al – 12Si) – 40Sn composite sample with the eutectic matrix has the highest wear resistance.

A Finite Element Modelling of Embrittlement in Composite Liquid Phase Sintered Heavy Alloys

1986 ◽  
Vol 108 (2) ◽  
pp. 159-162 ◽  
Author(s):  
D. Rittel ◽  
I. Roman ◽  
M. Bercovier
Keyword(s):  
Finite Element ◽  
Liquid Phase ◽  
Thermal Cycle ◽  
Finite Element Modelling ◽  
Room Temperature ◽  
Element Modelling ◽  
Room Temperature Ductility ◽  
Heavy Alloys ◽  
Finite Element Procedure ◽  
Sintered Alloys

Sintered tungsten base heavy alloys made of tungsten grains embedded in a nickel rich matrix can possess low room temperature ductility that may be improved by subsequent heat treatment. The sintering thermal cycle was simulated by a finite element procedure, and it was found that the vast differences in thermal and elastic properties of the microstructural components result in significant residual interfacial strains upon cooling to ambient temperature. These strains may contribute significantly to the low room temperature ductility of this class of liquid phase sintered alloys and should be relieved in order to improve ductility.

3D Phase-Field Simulation and Characterization of Microstructure Evolution during Liquid Phase Sintering

2014 ◽  
Vol 87 ◽  
pp. 132-138 ◽  
Author(s):  
Hamed Ravash ◽  
Eckard Specht ◽  
Jef Vleugels ◽  
Nele Moelans
Keyword(s):  
Liquid Phase ◽  
Grain Boundary ◽  
Coordination Number ◽  
Dihedral Angle ◽  
Phase Field ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Liquid Phase Sintering ◽  
Study Phase ◽  
Solid Liquid

Liquid phase sintering (LPS) is widely used as a materials processing technique for hightemperature applications. In LPS, particle-particle contact size and distribution, 3-D coordination number, connectivity, and contiguity are important microstructure parameters which, to a large extent, determine the mechanical properties of the sintered materials. These features all depend on the grain size, solid volume fraction and dihedral angle during sintering. The dihedral angle is an important parameter in LPS. It is the angle formed between the 2 solid-liquid interfaces at the intersection of a grain boundary with the liquid. A higher solid volume fraction, on the other hand, favors a larger 3-D coordination number, connectivity, and contiguity. In practice, studying the correlation between these parameters and direct measurement of them is not a trivial task. Among them, 3-D measurement of dihedral angle is believed to be the most challenging one. In the current study, phase-field modeling is employed to simulate LPS in two phase systems (solid and liquid). Simulations are performed for the different ratios of grain boundary to solid-liquid energies and the different solid volume fractions. To create initial structures with high solid volume fraction, an advanced particle packing algorithm is employed. An extended sparse bounding-box algorithm is used to speed-up the computations and makes it computationally efficient for 3-D simulations. Contiguity, connectivity, and three dimensional coordination number were measured in the self similar regime. The results were compared with empirical rules and experimental data and are used to estimate the mean 3-D dihedral angle.

Estimation of three-dimensional mean dihedral angle in a W–Ni–Fe alloy liquid-phase sintered in microgravity

2009 ◽  
Vol 61 (12) ◽  
pp. 1101-1104 ◽  
Author(s):  
W.B. Goodwin ◽  
M. Bharadwaj ◽  
Y. Mao ◽  
A.M. Gokhale ◽  
A. Gurumurthy ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Dihedral Angle ◽  
Three Dimensional

scholarly journals Microstructural development and evolution of liquid phase sintered Cr-Cu composites

2007 ◽  
Vol 39 (3) ◽  
pp. 249-258
Author(s):  
E. Khomenko ◽  
A. Ragulya ◽  
N. Lesnik ◽  
R. Minakova
Keyword(s):  
Liquid Phase ◽  
Dihedral Angle ◽  
Volume Fraction ◽  
Solid Phase ◽  
Liquid Phase Sintering ◽  
Microstructural Development ◽  
Angle Distribution ◽  
Refractory Component ◽  
Electrolytic Chromium ◽  
Component Particle

Features of the microstructure formation of Cr-Cu composites under impregnation followed by liquid phase sintering of reduced and electrolytic chromium powders at 1200?C in a vacuum of (2-4)?10-3Pa have been studied. The refractory component particle size distribution in the microstructure of samples with reduced chromium sintered for 60 min is shown to obey a normal logarithmic law; with distribution parameters being sensitive to the volume fraction of the refractory particles. The calculated values of the dihedral angle are close to the value of one of the modes in the experimental dihedral angle distribution for the microstructure of electrolytic chromium based samples (115?). The interfacial and interparticle surface energies ratio ?sl/?ss>0.5 is shown to correspond to theory for the Crs-Cul system in equilibrium, which indicates the presence of skeleton structure elements in the course of composition formation under liquid phase sintering (including the case of excess liquid phase). Experimentally determined interparticle and interfacial surface areas, solid particle contiguity and continuity are discussed in terms of concurrent diffusion-controlled particle coarsening (in Lifshitz, Slyozov and Wagner theory) and particle coalescence (in German?s model). The kinetics of shrinkage for the composites with 50...55 % solid-phase volume-fractions at heating and isothermal sintering in a vacuum at a temperature of 1200?C in terms of linearly viscous rheological theory are discussed.

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