Modeling of Solid-State Hot Press Bonding and Its Application to the Fabrication of Titanium Alloy Joints

Author(s):  
C. Zhang ◽  
H. Li ◽  
M. Q. Li

Solid-state hot press bonding is an advanced joining process wherein two specimens can be joined under high pressure for a period of time at an elevated temperature. The main step in hot press bonding is the void closure process. In the present study, a three-dimensional theoretical model for describing the void closure process is developed. In the model, the void closure process is divided into two stages: in the first stage, surface asperities are flattened by the time-independent local plastic flow mechanism, and isolated voids form at the bonding interface; in the second stage, the void closure is accomplished by three time-dependent mechanisms, namely, the viscoplastic flow mechanism, surface source diffusion mechanism, and interface source diffusion mechanism. The initial and ending conditions of these mechanisms are proposed. The model also includes an analysis of the effect of macroscopic deformation on void closure. Hot press bonding experiments of Ti–6Al–4V alloy are conducted to validate the model. The modeling predictions show good agreement with the experimental results.

2019 ◽  
Author(s):  
Sayan Mondal ◽  
Gary Tresadern ◽  
Jeremy Greenwood ◽  
Byungchan Kim ◽  
Joe Kaus ◽  
...  

<p>Optimizing the solubility of small molecules is important in a wide variety of contexts, including in drug discovery where the optimization of aqueous solubility is often crucial to achieve oral bioavailability. In such a context, solubility optimization cannot be successfully pursued by indiscriminate increases in polarity, which would likely reduce permeability and potency. Moreover, increasing polarity may not even improve solubility itself in many cases, if it stabilizes the solid-state form. Here we present a novel physics-based approach to predict the solubility of small molecules, that takes into account three-dimensional solid-state characteristics in addition to polarity. The calculated solubilities are in good agreement with experimental solubilities taken both from the literature as well as from several active pharmaceutical discovery projects. This computational approach enables strategies to optimize solubility by disrupting the three-dimensional solid-state packing of novel chemical matter, illustrated here for an active medicinal chemistry campaign.</p>


2003 ◽  
pp. 956 ◽  
Author(s):  
Günter Margraf ◽  
Jan W. Bats ◽  
Michael Bolte ◽  
Hans-Wolfram Lerner ◽  
Matthias Wagner

2013 ◽  
Vol 69 (12) ◽  
pp. i85-i86 ◽  
Author(s):  
Youssef Ben Smida ◽  
Abderrahmen Guesmi ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

The title compound, trisodium dicobalt(II) (arsenate/phosphate) (diarsenate/diphosphate), was prepared by a solid-state reaction. It is isostructural with Na3Co2AsO4As2O7. The framework shows the presence of CoX22O12(X2 is statistically disordered with As0.95P0.05) units formed by sharing corners between Co1O6octahedra andX22O7groups. These units form layers perpendicular to [010]. Co2O6octahedra andX1O4(X1 = As0.54P0.46) tetrahedra form Co2X1O8chains parallel to [001]. Cohesion between layers and chains is ensured by theX22O7groups, giving rise to a three-dimensional framework with broad tunnels, running along thea- andc-axis directions, in which the Na+ions reside. The two Co2+cations, theX1 site and three of the seven O atoms lie on special positions, with site symmetries 2 andmfor the Co,mfor theX1, and 2 andm(× 2) for the O sites. One of two Na atoms is disordered over three special positions [occupancy ratios 0.877 (10):0.110 (13):0.066 (9)] and the other is in a general position with full occupancy. A comparison between structures such as K2CdP2O7, α-NaTiP2O7and K2MoO2P2O7is made. The proposed structural model is supported by charge-distribution (CHARDI) analysis and bond-valence-sum (BVS) calculations. The distortion of the coordination polyhedra is analyzed by means of the effective coordination number.


Ceramics ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 421-436
Author(s):  
Aamir Iqbal Waidha ◽  
Vanita Vanita ◽  
Oliver Clemens

Composite electrolytes containing lithium ion conducting polymer matrix and ceramic filler are promising solid-state electrolytes for all solid-state lithium ion batteries due to their wide electrochemical stability window, high lithium ion conductivity and low electrode/electrolyte interfacial resistance. In this study, we report on the polymer infiltration of porous thin films of aluminum-doped cubic garnet fabricated via a combination of nebulized spray pyrolysis and spin coating with subsequent post annealing at 1173 K. This method offers a simple and easy route for the fabrication of a three-dimensional porous garnet network with a thickness in the range of 50 to 100 µm, which could be used as the ceramic backbone providing a continuous pathway for lithium ion transport in composite electrolytes. The porous microstructure of the fabricated thin films is confirmed via scanning electron microscopy. Ionic conductivity of the pristine films is determined via electrochemical impedance spectroscopy. We show that annealing times have a significant impact on the ionic conductivity of the films. The subsequent polymer infiltration of the porous garnet films shows a maximum ionic conductivity of 5.3 × 10−7 S cm−1 at 298 K, which is six orders of magnitude higher than the pristine porous garnet film.


2021 ◽  
Vol 2021 (29) ◽  
pp. 136-140
Author(s):  
Dorukalp Durmus

The quality of building electric lighting systems can be assessed using color rendition metrics. However, color rendition metrics are limited in quantifying tunable solid-state light sources, since tunable lighting systems can generate a vast number of different white light spectra, providing flexibility in terms of color quality and energy efficiency. Previous research suggests that color rendition is multi-dimensional in nature, and it cannot be simplified to a single number. Color shifts under a test light source in comparison to a reference illuminant, changes in color gamut, and color discrimination are important dimensions of the quality of electric light sources, which are not captured by a single-numbered metric. To address the challenges in color rendition characterization of modern solid-state light sources, the development of a multi-dimensional color rendition space is proposed. The proposed continuous measure can quantify the change in color rendition ability of tunable solid-state light devices with caveats. Future work, discretization of the continuous color rendition space, will be carried out to address the shortcomings of a continuous three-dimensional space.


Author(s):  
Wei Wang ◽  
Wan-Yun Xie ◽  
Fei-Xiang Zhou ◽  
Liang Chen ◽  
Minjie Zhou ◽  
...  

2022 ◽  
Author(s):  
Xiang Han ◽  
Tiantian Wu ◽  
Lanhui Gu ◽  
Dian Tian

A three-dimensional (3D) metal-organic framework containing Li-oxygen clusters, namely {[Li2(IPA)]·DMF}n (1) (H2IPA = isophthalic acid), has been constructed under solvothermal conditions. The Li-based MOF can be applied to lithium energy...


2018 ◽  
Vol 775 ◽  
pp. 493-498 ◽  
Author(s):  
Azlan Ahmad ◽  
Mohd Amri Lajis ◽  
Shazarel Shamsudin ◽  
Nur Kamilah Yusuf

This study proposes of harmonizing the original approach of aluminium alloy recycling through hot press forging. By eradicating the melting phase, most of the waste generation can be significantly reduced. To cope with the technology revolution, the finite element is utilised to predict the material behaviour without practically executing the trial. By employing three-dimensional finite element analysis through DEFORM 3D, the evaluations were demonstrated by simulating the isothermal forging process. The flow stress of the material was modified to adequate with the aluminium-based metal matrix composite used in the actual experiment. To that extent, this study found out that the strain of the workpiece had gradually increased on each step. A reduction of ~10% of the flesh observed in the simulation is roughly the same as existed on the experiment workpiece. Above all, the simulation conducted abides by the standard and follows the actual practice that has been done previously. Through the finite element utilization, this study discussed the performance of the recycled based composite. The result presented here may facilitate improvement in the recycling issue and also conserved the environment for the better future.


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