Diffusion Path Analysis Research Articles

Application of Diffusion Path Analysis to Understand the Mechanisms of Transient Liquid-Phase Bonding in the Ni-Si-B System

Diffusion path analysis was applied to the Ni-Si-B system to explain the deviation from classical transient liquid-phase bonding observed when using multicomponent systems containing Boron as a melting point depressant. This was achieved using a combination of differential scanning calorimetry, SEM-EDS microstructural and chemical analysis, and Thermo-Calc modeling software of Ni/Ni-Si-B couples. Compositional analysis identified differing distributions of B and Si across the braze joint which were mapped onto isothermal sections of Thermo-calc-generated phase diagrams. Below 1093 °C, the inevitable formation of diffusionally affected zone (DAZ) and isothermally solidified zone is a direct consequence of the need for phase equilibria in the Ni-Si-B ternary system and is predicted by diffusion path analysis. Above 1100 °C, diffusion path analysis also correctly predicts a persistent liquid phase observed to occur through the melting of the DAZ (i.e., a γ-Ni(Si)-Ni3B eutectic reaction).

Knowledge diffusion path analysis of data quality literature: A main path analysis

Abstract This study presents a unique approach in investigating the knowledge diffusion structure for the field of data quality through an analysis of the main paths. We study a dataset of 1880 papers to explore the knowledge diffusion path, using citation data to build the citation network. The main paths are then investigated and visualized via social network analysis. This paper takes three different main path analyses, namely local, global, and key-route, to depict the knowledge diffusion path and additionally implements the g -index and h -index to evaluate the most important journals and researchers in the data quality domain.

Sintering mechanisms of blended Ti6Al4V powder from diffusion path analysis

The sintering of master alloy-blended Ti6Al4V powder has been investigated to elucidate the mechanisms of sintering. Both blended powder compacts and diffusion couple samples were investigated using backscattered imaging and energy dispersive analysis to determine the phases present, and the diffusion path for sintering which has not been previously reported for this system. Transient liquid-phase sintering does not occur, and it is shown for the first time that the reason for the rapid sintering of this material in the temperature range of 1000–1150 °C is due to enhanced diffusion kinetics resulting from a combination of the concentration gradient and stress induced by a phase transformation in the ternary system. The results of this study have implications for the development of blended master alloy combinations in other powder metallurgy systems.

Diffusion paths in single-phase ternary metal systems

An analysis of diffusion paths in single-phase ternary metal systems Co–Fe–Ni and Cu–Fe–Ni on the basis of the phenomenological interdiffusion model using effective interdiffusion coefficients is presented. The peculiarities of practical application of effective interdiffusion coefficients of components for calculating diffusion paths in ternary systems are analysed. It is done on the basis of the relationship between effective interdiffusion coefficients and the diffusion paths. The results were found to be in good agreement with experimental data for the ternary systems Co–Ni–Fe and Cu–Ni–Fe. It is shown that deviation of the diffusion path from linearity in ternary single-phase diffusion couple in the system Cu–Ni–Fe mainly depends on the thermodynamic properties of the system.

Analysis of diffusion paths for photovoltaic technology based on experience curves

This paper assesses the prospects for diffusion of photovoltaic (PV) technology for electricity generation in grid-connected systems. The analysis begins with the calculation of the break-even price of PV systems and modules, which is the price that can assure commercial viability without incentives or subsidies. The calculated average break-even price of PV systems for building-integrated applications is about $3.2/W p, but can go up to about $4.5/W p in areas with very good solar irradiation and if a low real discount rate is applied. These are higher values than the break-even prices estimated in the literature to date. PV system break-even prices for intermediate load generation in utility-owned systems are also calculated, their average being about $1/W p. The methodology of experience curves is used to predict what would be the different levels of cumulative world PV shipments required to reach the calculated break-even prices of PV systems, assuming different trends in the relationship between price and the increase in cumulative shipments. The years in which the break-even levels of cumulative shipments could be theoretically obtained are then calculated by considering different market growth rates. Photovoltaics could enter the niche of building-integrated applications without incentives in the first years of the next decade, provided that the PR is 80% and the average annual world market growth rate is at least 15%. The final part of the paper analyzes the niche markets or applications that seem promising for the diffusion of photovoltaics in the next few years.

Diffusion path analysis of dynamic behavior of oil‐water‐surfactant systems

AbstractThe diffusional processes that occur when oil contacts an aqueous surfactant solution have been investigated. These are pertinent to enhanced oil recovery by surfactant flooding and to detergency in certain systems. The theory of diffusion paths was used to solve the diffusion equations for a model pseudoternary system. Although detailed comparison with experimental results was not possible due to a lack of necessary data, calculated diffusion paths and interface velocities were found to be useful for explaining various phenomena observed experimentally in an oil recovery system.Because the surfactant “solutions” studied commonly exist as dispersions of liquid crystal, extension of the theory to allow for initial compositions in two‐phase regions was carried out. Also novel was investigation of the effect of the three‐phase regions that occur in these systems on the position and shape of calculated diffusion paths.

Analysis of diffusion paths in a three-component system

The analytical solution for the case of one-dimensional diffusion in a homogeneous, three-component system, in which the diffusion coefficients are assumed to be independent of concentration, is subjected to a more detailed analysis than was given in a previous paper. An analytical relationship is derived that enables one to choose boundary conditions in such a way as to eliminate all physically meaningless special solutions containing negative concentrations. It is shown that the magnitude of the ratio of an off-diagonal coefficient to the sum of the principal diffusion coefficients may be used as one of the criteria in the procedure. Further, a generalization of the analysis enables one to specify the parameters that control the depths of minima in non-monotonic concentration-penetration curves which are physically meaningful.