Development of an Aging Process for Friction Stir Extruded Joints

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Adam W. Jarrell ◽  
Brayden C. Terry ◽  
Alvin M. Strauss ◽  
George E. Cook
Keyword(s):  
Heat Treatment ◽  
Aging Process ◽  
Dissimilar Materials ◽  
Sem Analysis ◽  
Post Processing ◽  
Electron Microscopic ◽  
Friction Stir ◽  
Hardening Process ◽  
Scanning Electron Microscopic ◽  
Friction Stir Extrusion

Abstract Friction stir extrusion is a derivative process of friction stir welding for joining dissimilar materials. The process forms a mechanical joint through extrusion to form interlocking features between two metals. When joining AA6061-T6 to mild steel through extrusion of a dovetail, much of the T6 heat treatment of the aluminum in and around the weld is lost during the process. This paper details the examination of a post-processing aging process to return AA6061 to the T6 condition. Through a 10-h precipitation hardening process at 170 °C. The welds experienced a 23.9% increase in the tensile strength from 2193 N as-welded to 2718 N after 10 h. Hardness measurements showed a return close to T6 conditions in both the weld nugget and extruded material, 67.5–83.5 HRF and 54.7–81.8 HRF, respectively, during the heat treatment period. The steel showed no substantial changes in hardness during the heat treatment. Scanning electron microscopic (SEM) analysis revealed significant changes in the sizes of two species of inclusions within the aluminum during both the welding and post-processing.

scholarly journals Effect of orientation of initially formed grains on the final morphology of electrodeposited lead

2014 ◽  
Vol 79 (8) ◽  
pp. 993-1005 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Konstantin Popov ◽  
Evica Ivanovic ◽  
Goran Brankovic
Keyword(s):  
Growth Process ◽  
Sem Analysis ◽  
Diffusion Control ◽  
Lateral Side ◽  
Electron Microscopic ◽  
Initial Shape ◽  
Hexagonal Shape ◽  
Initial Stage ◽  
Scanning Electron Microscopic ◽  
Spherical Diffusion

The processes of Pb electrodeposition in the diffusion control were examined by the scanning electron microscopic (SEM) analysis of the formed crystals. Orientation of grains of hexagonal shape formed in the initial stage of electrodeposition strongly affected the final morphology of Pb crystals. Formation of Pb crystals of the different shape from the same initial shape was discussed by the effect of orientation of initially formed grains on the type of diffusion control. The spherical diffusion layer was formed around the tip of the hexagonal shaped grain oriented by the tip towards the bulk of solution leading to formation of elongated crystals in the growth process. On the other hand, the cylindrical type of diffusion was responsible for growth of hexagonal shaped grains oriented by the lateral side towards the bulk of solution. Pb crystals with well defined sides parallel to the surface area of macroelectrode were formed by this type of diffusion.

Studying Pressure Induced Whiskers Formation from Sn-Rich Surfaces

2014 ◽  
Vol 790-791 ◽  
pp. 271-276 ◽  
Author(s):  
Anna Sycheva ◽  
Adam Radanyi ◽  
Zoltán Gácsi
Keyword(s):  
Heat Treatment ◽  
Mechanical Load ◽  
Short Circuit ◽  
Electronic Devices ◽  
Control Unit ◽  
Tin Whiskers ◽  
Tin Whisker ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Sem Imaging

Whiskers formed on the lead-free tin surfaces pose a serious risk to small electronic devices causing a short circuit and leading to the component/device failure. The present research was focused on the investigation of tin whisker formation on a motor control unit sockets made of tin coated copper, applying to the specimen mechanical load alone or together with heat treatment/electric current. Scanning Electron Microscopic (SEM) imaging was applied in order to study the microstructure of tin whiskers obtained, their length and number at the boundary of each imprint. If the mechanical stress increases from 1000 to 5000 MPa, the average number of whiskers and possible formation spots also increase from 570 to 1300. The length of whiskers varied from 3 μm after 0.5 h to 5.5 μm after 3 hours of exposition. It has been found that heat treatment at 150°C for 1 hour significantly reduces the number of whiskers (on average 6 times as few) formed. Therefore, the threat of failure of the electronic equipment is reduced.

scholarly journals Exploration of Thread for their Possible use in Fabrication of Low Cost Diagnostic Microfluidic Device

2018 ◽  
Vol 15 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Rakesh B Kabariya ◽  
Vimal M Ramani
Keyword(s):  
Capillary Flow ◽  
Low Cost ◽  
Sem Analysis ◽  
Absorption Capacity ◽  
Great Promise ◽  
Diagnostic Purpose ◽  
Electron Microscopic ◽  
Cotton Thread ◽  
Scanning Electron Microscopic ◽  
The Ideal

The emerging concept of thread-based microfluidics has shown great promise for application to inexpensive disease detection and environmental monitoring. This paper describe the properties of thread for the development of thread based low-cost microfluidics device for the diagnostic, food safety and environmental assay. Various properties of thread like capillary flow, wicking capacity and absorption capacity, make them important to fabricate the low-cost microfluidics device. In this paper, three different thread sample viz. cotton yarn, cotton thread and spun thread were taken and different properties like wicking capacity, fluid capillary flow, absorption capacity were measured as well as Scanning Electron Microscopic (SEM) analysis of the same was also carried out to study the morphology and texture of thread fibers. Data obtained from result indicate that the cotton thread having all the ideal characteristic to fabricate the diagnostic device and thus it is suitable for the fabrication of thread based microfluidics device for the diagnostic purpose.

TAGUCHI GREY RELATIONAL MULTI-RESPONSE EXPERIMENTAL OPTIMIZATION ON MODIFICATION OF Al-6061 SURFACE USING Si–Cu GREEN COMPACT TOOL IN EDM

2021 ◽  
pp. 2150073
Author(s):  
RASHED MUSTAFA MAZARBHUIYA ◽  
BHARGAB MADHAB BARUA ◽  
MANESWAR RAHANG
Keyword(s):  
Surface Modification ◽  
Sem Analysis ◽  
Green Compact ◽  
Electron Microscopic ◽  
Work Surface ◽  
Optical Micrograph ◽  
Material Deposition ◽  
Scanning Electron Microscopic ◽  
Grey Relational ◽  
Pulse On Time

This paper presents the surface modification of aluminium-6061 by electric discharge machining (EDM). Si–Cu powder metallurgical green compact tool is used to deposit its material on to the work surface under reverse polarity of EDM. Compact load, current and pulse on-time are selected control parameters. Material deposition rate (MDR), tool wear rate (TWR) and surface roughness ([Formula: see text] are considered as process outputs. Scanning electron microscopic (SEM) analysis and energy dispersive X-ray (EDX) analysis show the presence of tool materials in the deposit of work surface. Olympus optical micrograph shows an average thickness of the deposited layer to be 18.73[Formula: see text][Formula: see text]m. The hardness of the deposited layer is found to be 268[Formula: see text]HV. Analysis of variance (ANOVA) shows the compact load to be the most effective parameter on surface modification followed by pulse on-time and current, respectively.

Effect of post processing heat treatment on friction stir welded/processed aluminum based alloys and composites

2021 ◽  
Vol 35 ◽  
pp. 96-105
Author(s):  
Pabitra Maji ◽  
Rahul Kanti Nath ◽  
Ranit Karmakar ◽  
Pritam Paul ◽  
R.K. Bhogendro Meitei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Post Processing ◽  
Friction Stir

scholarly journals Synthesis and Characterization of P3HT/Metal Nanoparticles

2019 ◽  
Vol 17 (43) ◽  
pp. 122-127
Author(s):  
Mustafa A. Mustafa
Keyword(s):  
Metallic Nanoparticles ◽  
Chemical Interaction ◽  
Pulsed Laser ◽  
Sem Analysis ◽  
Electron Microscopic ◽  
X Ray ◽  
Spherical Structure ◽  
Scanning Electron Microscopic ◽  
Fabrication And Characterization

In this work the fabrication and characterization of poly(3-hexylthiophene) P3HT-metallic nanoparticles (Ag, Al). Pulsed Laser Ablation (PLA) technique was used to synthesis the nanoparticles in liquid. The Fourier Transformer Infrared (FTIR) for all samples indicate the chemical interaction between the polymer and the nanoparticles. Scanning Electron Microscopic (SEM) analysis showed the particle size for P3HT-AgNps samples between 44.50 nanometers as well the spherical structure. While for P3HT-AlNps samples was flakes shape. Energy Dispersive X-ray (EDX) spectra show the existing of amount of metallic nanoparticles.

Mechanism of PVC’s Solid-Phase Photocatalytic Degradation Enhanced by Plasma

2007 ◽  
Vol 544-545 ◽  
pp. 155-158
Author(s):  
Xiao Jing Li ◽  
Guan Jun Qiao ◽  
Jie Rong Chen
Keyword(s):  
Free Radicals ◽  
Photocatalytic Degradation ◽  
Solid Phase ◽  
Ambient Air ◽  
Nitrogen Plasma ◽  
Sem Analysis ◽  
Electron Microscopic ◽  
Pvc Film ◽  
Spin Resonance ◽  
Scanning Electron Microscopic

The solid-phase photocatalytic degradation of poly (vinyl chloride) (PVC) films was investigated in ambient air. The photodegradation of the PVC and PVC-TiO2 was compared with that of plasma-treated PVC and plasma-treated PVC-TiO2 performing a weight loss monitoring and scanning electron microscopic (SEM) analysis. The SEM of the PVC-TiO2 film treated by plasma showed many cracks on the surface after photodegradation. Furthermore, the surface wettability and surface structure of PVC after nitrogen plasma treatment was characterized by contact angle, surface tension, and electron spin resonance (ESR). The experiment indicated that the surface free energy and wettability of PVC treated by plasma increased greatly. ESR revealed that the signal of radicals on the surface of the plasma-treated PVC film was enhanced after treatment. The free radicals on the surface of plasma-treated PVC possibly decreased the activating energy of photocatalytic reaction, which belongs to the free radicals reaction, because the chemical activity of the free radicals was high. According to these findings, a mechanism on the photodegradation of plasma-treated PVC-TiO2 is proposed.

Friction Stir Extrusion: A new process for joining dissimilar materials

2015 ◽  
Vol 5 ◽  
pp. 25-28 ◽  
Author(s):  
William T. Evans ◽  
Brian T. Gibson ◽  
Jay T. Reynolds ◽  
Alvin M. Strauss ◽  
George E. Cook
Keyword(s):  
Dissimilar Materials ◽  
Friction Stir ◽  
New Process ◽  
Friction Stir Extrusion

Enamel Deproteinization before Acid Etching – A Scanning Electron Microscopic Observation

2010 ◽  
Vol 35 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Bhoomika Ahuja ◽  
Ramakrishna Yeluri ◽  
M Sudhindra Baliga ◽  
AK Munshi
Keyword(s):  
Phosphoric Acid ◽  
Sem Analysis ◽  
Enamel Surface ◽  
Electron Microscopic ◽  
Etching Pattern ◽  
Significant Difference ◽  
Scanning Electron Microscopic ◽  
Group 2 ◽  
Scanning Electron ◽  
Group 1

Objectives: This study was undertaken to evaluate the topographical features of enamel surface deproteinized with sodium hypochlorite (NaOCl) and etched with phosphoric acid (H3PO4) compared to phosphoric acid alone using Scanning Electron Microscopic (SEM) Analysis. Study Design: 30 enamel blocks of 1mm2 from ten human sound extracted permanent molars were obtained and treated as under: Group 1 (10 blocks): Enamel surface was etched with 37% H3PO4 gel for 15 seconds. Group 2 (10 blocks):Enamel surface was treated with 5.25% NaOCl for 60 seconds and then etched with 37% H3PO4 gel for 15 seconds. 10 enamel blocks were included in the control group where no treatment was carried out. The samples were subjected to SEM analysis and 5 microphotographs of each sample were obtained at 500X magnification and evaluated for the quality of etching pattern of the enamel in percentage (%) using Auto-CAD 2007 software. Results: Mean values of etching pattern in Group 1 being 55.76% and Group 2 being 53.58%. No significant difference was observed between the two groups. Conclusion: The use of 37% phosphoric acid for 15 seconds still remains the best method for pretreatment of enamel.

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