Introduction

2005 ◽  
pp. 1-46
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Fluid Flow ◽  
Surface Energy ◽  
Environmental Aspects ◽  
Solid Materials ◽  
Principal Characteristics ◽  
Parent Materials ◽  
Joint Gap ◽  
New Phase

Abstract Brazing and soldering jointly represent one of several methods for joining solid materials. This chapter summarizes the principal characteristics of the various joining methods. It then discusses key parameters of brazing including surface energy and tension, wetting and contact angle, fluid flow, filler spreading characteristics, surface roughness of components, dissolution of parent materials, new phase formations, significance of the joint gap, and the strength of metals. The chapter also describes issues in processing aspects that must be considered when designing a joint, and the health, safety, and environmental aspects of brazing.

Introduction

2004 ◽  
pp. 1-47
Keyword(s):  
Surface Tension ◽  
Adhesive Bonding ◽  
Solid Materials ◽  
Principal Characteristics ◽  
Parent Materials ◽  
Intermetallic Growth ◽  
Joint Gap ◽  
Mechanical Fastening ◽  
And Diffusion ◽  
Solid State Joining

Abstract Soldering and brazing represent one of several types of methods for joining solid materials. These methods may be classified as mechanical fastening, adhesive bonding, soldering and brazing, welding, and solid-state joining. This chapter summarizes the principal characteristics of these joining methods. It presents a comparison between solders and brazes. Further details on pressure welding and diffusion bonding are also provided. The chapter briefly reviews the concepts of surface energy and surface tension, wetting and contact angle, fluid flow, filler spreading characteristics, surface roughness of components, dissolution of parent materials and intermetallic growth, significance of the joint gap, and the strength of metals. It examines the principal aspects related to the design and application of soldering processes.

Addition of Cellulose Nanofibers to Control Surface Roughness for Hydrophobic Ceramic Coatings

2021 ◽  
Vol 21 (8) ◽  
pp. 4492-4497
Author(s):  
Eun Ae Shin ◽  
Gye Hyeon Kim ◽  
Jeyoung Jung ◽  
Sang Bong Lee ◽  
Chang Kee Lee
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Ceramic Coating ◽  
Cellulose Nanofibers ◽  
Ceramic Coatings ◽  
Coating Material ◽  
Textured Surface ◽  
Water Contact

Hydrophobic ceramic coatings are used for a variety of applications. Generally, hydrophobic coating surfaces are obtained by reducing the surface energy of the coating material or by forming a highly textured surface. Reducing the surface energy of the coating material requires additional costs and processing and changes the surface properties of the ceramic coating. In this study, we introduce a simple method to improve the hydrophobicity of ceramic coatings by implementing a textured surface without chemical modification of the surface. The ceramic coating solution was first prepared by adding cellulose nanofibers (CNFs) and then applied to a polypropylene (PP) substrate. The surface roughness increased as the amount of added CNFs increased, increasing the water contact angle of the surface. When the amount of CNFs added was corresponding to 10% of the solid content, the surface roughness average of the area was 43.8 μm. This is an increase of approximately 140% from 3.1 μm (the value of the surface roughness of the surface without added CNFs). In addition, the water contact angle of the coating with added CNF increased to 145.0°, which was 46% higher than that without the CNFs. The hydrophobicity of ceramic coatings with added CNFs was better because of changes in the surface topography. After coating and drying, the CNFs randomly accumulated inside the ceramic coating layer, forming a textured surface. Thus, hydrophobicity was improved by implementing a rugged ceramic surface without revealing the surface of the CNFs inside the ceramic layer.

Preparation of Hydrophobic Nylon Fabric

2016 ◽  
Vol 11 (1) ◽  
pp. 155892501601100
Author(s):  
Jinmei Du ◽  
Lulu Zhang ◽  
Jing Dong ◽  
Ying Li ◽  
Changhai Xu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Sem Images ◽  
Water Contact ◽  
Carboxyl Content ◽  
Factors Affecting ◽  
Nylon Fabric ◽  
Butanetetracarboxylic Acid

Surface roughness and surface energy are two important factors affecting the hydrophobicity of nylon fabric. In this study, nylon fabric was treated for hydrophobicity with tetrabutyltitanate (TBT) and octadecylamine (OA) which were respectively responsible for increasing surface roughness and reducing surface energy. In order to enhance the hydrophobicity, In order to further enhance hydrophobicity by increasing available reactive sites, 1,2,3,4–butanetetracarboxylic acid (BTCA) was applied as a pretreatment to the nylon fabric It was found that the carboxyl content of nylon was increased by the BTCA pretreatment. SEM images showed that the TBT treatment produced small particles on nylon fabric which made surface rough. The water contact angle of nylon fabric treated with BTCA, TBT and OA was measured to be 134°, which was much greater than the water contact angle of nylon fabric treated only with OA. This indicated that the surface roughness resulting from the TBT treatment played an important role in improving hydrophobicity of the treated nylon fabric. The resistance to water penetration and the repellency of water spray of nylon fabric treated with BTCA, TBT and OA were respectively measured to be 27.64 mbar and 85 out of 100.

Improved Hydrophobicity of Silicon Dioxide Integrated Zinc-Tellurite Glass Surface

2017 ◽  
Vol 268 ◽  
pp. 87-91
Author(s):  
Syarinie Azmi ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Glass Surface ◽  
Tellurite Glass ◽  
Hydrophobic Surfaces ◽  
Water Contact ◽  
Host Matrix ◽  
The Impact

Economically viable and maintenance free glass surfaces with improved hydrophobicity are highly demanding in the recent nanotechnology era. Deposition of pollutants and dirt on glass surface that not only causes visual obscurity but also damages the cultural heritages are still to be researched intensely. It is documented that excellent hydrophobic surfaces (with contact angle greater than 90o) can be achieved by controlling the surface wettability, where liquid droplets remain spherical on such surfaces. Selection of materials and the preparation method play a significant role towards such accomplishments. Stirred by this idea, we explored the feasibility of fabricating super-hydrophobic tellurite glass systems by facilely varying the compositions of different constituents. Highly transparent and thermally stable ternary tellurite glass system with chemical composition of (80-x)TeO2 – xSiO2 – 20ZnO, where x = 0.00 to 0.20 mol% are synthesized via conventional melt-quenching method. Samples are characterized using Atomic Force Microscopy (AFM) and contact angle measurements. The impact of SiO2 concentrations variation on the surface roughness, surface energy, and hydrophobic properties are inspected. Glass surface roughness as much as 9.885 nm is attained. The optimal value of water contact angle is discerned to be 101.02° for 0.1 mol% of SiO2 incorporation into the amorphous tellurite host matrix. Besides, the surface energy revealed an inverse proportionality to the water contact angle. This achieved contact angle (greater than 90°) makes this hydrophobic glass surface beneficial for diverse applications. It is established that the present glass composition may be prospective for the development of super-hydrophobic surfaces.

scholarly journals Characterization Of Dielectric Barrier Discharge (DBD) Produced In Air At Atmospheric Pressure And Its Application In Surface Modification Of High-Density Polyethylene (HDPE)

2020 ◽  
Vol 1 (1) ◽  
pp. 27-35
Author(s):  
Rajesh Prakash Guragain ◽  
H B Baniya ◽  
S Dhungana ◽  
S Gautam ◽  
B P. Pandey ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Dielectric Barrier Discharge ◽  
High Density Polyethylene ◽  
Barrier Discharge ◽  
Sem Analysis ◽  
High Density ◽  
Optical Methods ◽  
Dielectric Barrier

The low surface energy of HDPE limits its industrial uses as it is not suitable for printing and adhesion. The main aim of this work is to improve the wetting properties of high-density polyethylene (HDPE) using air dielectric barrier discharge (DBD) operating at the line frequency (50 Hz). The estimation of electron temperature and electron density has been done by electrical and optical methods. The surface roughness of the control and plasma treated polymer film is analysed by contact angle (CA) measurement, surface energy measurement and scanning electron microscope (SEM) analysis. The contact angle was found to be suppressed from 93.180±2.00 to 63.750±0.880 after 10s of plasma treatment which implied that the surface property had changed to a hydrophilic state caused by an increase in the surface roughness.

Effect of Etching and Modification on the Hydrophobic Angle of Epoxy/Poss Nanomaterials

2020 ◽  
Vol 15 (12) ◽  
pp. 1502-1507
Author(s):  
Yanhong Fang ◽  
Ping Wang ◽  
Lifang Sun ◽  
Linhong Wang
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Hydrochloric Acid ◽  
Surface Energy ◽  
Stearic Acid ◽  
Acid Etching ◽  
Energy Materials ◽  
Nano Structure ◽  
Low Surface Energy ◽  
Long Time

In this study, simple and feasible methods are used to increase the hydrophobicity of EP-POSS, that is, etching with concentrated hydrochloric acid and concentrated ammonia water, followed by modification with polytetrafluoroethylene and stearic acid. The principle of the study is to increase the hydrophobic angle of EP-POSS by immersion in concentrated hydrochloric acid and concentrated ammonia for a sufficiently long time, followed by modification with low-surface-energy materials, i.e., polytetrafluoroethylene and stearic acid. The contact angle of EP-POSS increased from 100° to 133° after immersing in 3 mol/L hydrochloric acid for 12 min. Compared to hydrochloric acid, the surface roughness and contact angel were not changed significantly by immersing in concentrated ammonia for 4 hours. The contact angle was not changed obviously after immersing in 0.1 mol/L polytetrafluoroethylene for 24 h, and only changed from 135° to 136° when immersed in 0.1 mol/L stearic acid. It shows that PTFE and stearic acid hasn?t effectively grafted to the surface of EP-POSS, and has no effect to the micro-nano structure of EP-POSS. According to the experimental results, hydrochloric acid etching is the proper way to enhance EP-POSS contact angel. According to further investigates, it can be determined that treating EP-POSS at 40 °C for 12 min with 3 mol/L hydrochloric acid can significantly improve its hydrophobicity, thus, the hydrophobic performance of EP-POSS is considerably improved.

scholarly journals Study on Delamination Between Polymer Materials and Metals in IC Packaging Process

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 940 ◽  
Author(s):  
Cheng-Tang Pan ◽  
Shao-Yu Wang ◽  
Chung-Kun Yen ◽  
Chien-Kai Ho ◽  
Jhan-Foug Yen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Heat Sink ◽  
Ball Grid Array ◽  
Simulation Software ◽  
Polymer Materials ◽  
Packaging Process ◽  
Finite Element Analysis Simulation ◽  
Plastic Ball

The electronic package interconnects electronic signals from one area to another and package delamination is a serious problem in the configuration of materials. This study focused on decreasing the delamination of the low-profile fine pitch ball grid array (LFBGA) and plastic ball grid array (PBGA) packages in terms of polymer thermal issue, metal bonding and bonding mechanisms. PBGA and LFBGA are a very common type of packaging processes in the electronics industry. The present study dealt first with delamination of the LFBGA packaging, through characterization and determination of physical and chemical properties such as surface roughness, surface energy, and contact angle. The relationship between surface roughness and delamination was verified through various roughness bonding experiments. In addition, the surface energy was determined by measuring the contact angle after cleaning the metal surface of Cu, Ni and Cr with Ar + O2 gas, and, this gas plasma treatment was applied to enhance the adhesive properties. The compositions of the surface were analyzed through an X-ray photoelectron spectroscopy (XPS). Also, the delamination issue between the corner of the heat sink cap and the epoxy resin was observed for delamination of the LFBGA packaging. Further, this study analyzed the PBGA packaging process through the finite element analysis simulation software ANSYS. To improve the heat sink cap delamination issue of the PBGA, a new chamfer design of the corner seat was streamlined to decrease the stress value and delamination. Besides, the simulation results demonstrated that the stress value reduced after increasing the shoulder length. The results implicate that the stress value is inversely proportional to the shoulder width and the chamfer radius. This study demonstrated that the optimization in design was able reduce the delamination phenomena in configuration material.

scholarly journals Air, helium and water leakage in rubber O-ring seals with application to syringes

2021 ◽  
Author(s):  
Carine Huon ◽  
Avinash Tiwari ◽  
Cinzia Rotella ◽  
Paolo Mangiagalli ◽  
bo persson
Keyword(s):  
Surface Roughness ◽  
Fluid Flow ◽  
Surface Energy ◽  
Viscoelastic Properties ◽  
Gas Flow ◽  
Laplace Pressure ◽  
Water Leakage ◽  
Random Surface ◽  
Interfacial Surface ◽  
Interfacial Fluid

Abstract We study the leakage of fluids (liquids or gases) in syringes with glass barrel, steel plunger and rubber O-ring stopper. The leakrate depends on the interfacial surface roughness and on the viscoelastic properties of the rubber. Random surface roughness is produced by sandblasting the rubber O-rings. We present a very simple theory for gas flow which takes into account both the diffusive and ballistic flow. The theory shows that the interfacial fluid flow (leakage) channels are so narrow that the gas flow is mainly ballistic (the so called Knudsen limit). We compare the leakrate obtained using air and helium. For barrels filled with water we observe no leakage even if leakage occurs for gases. We interpret this as resulting from capillary (Laplace pressure or surface energy) effects.

A new method for quantifying the blocking of coated paperboard

TAPPI Journal ◽  
2010 ◽  
Vol 9 (5) ◽  
pp. 29-35 ◽  
Author(s):  
PAULINE SKILLINGTON ◽  
YOLANDE R. SCHOEMAN ◽  
VALESKA CLOETE ◽  
PATRICE C. HARTMANN
Keyword(s):  
Surface Roughness ◽  
Fatty Acid ◽  
Surface Energy ◽  
Film Thickness ◽  
External Factors ◽  
Additive Concentration ◽  
Pressure Surface ◽  
Fatty Acid Amides ◽  
Coated Surfaces ◽  
Definite Period

Blocking is undesired adhesion between two surfaces when subjected to pressure and temperature constraints. Blocking between two coated paperboards in contact with each other may be caused by inter-diffusion, adsorption, or electrostatic forces occurring between the respective coating surfaces. These interactions are influenced by factors such as the temperature, pressure, surface roughness, and surface energy. Blocking potentially can be reduced by adjusting these factors, or by using antiblocking additives such as talc, amorphous silica, fatty acid amides, or polymeric waxes. We developed a method of quantifying blocking using a rheometer. Coated surfaces were put in contact with each other with controlled pressure and temperature for a definite period. We then measured the work necessary to pull the two surfaces apart. This was a reproducible way to accurately quantify blocking. The method was applied to determine the effect external factors have on the blocking tendency of coated paperboards, i.e., antiblocking additive concentration, film thickness, temperature, and humidity.

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