scholarly journals Fabrication of Metallic Glass Layers on Al Alloys with Improved Corrosion Resistance and Micro-Hardness by Pulsed Electrical Discharge Treatment

2018 ◽  
Vol 8 (6) ◽  
pp. 956 ◽  
Author(s):  
Han Dai ◽  
Jie Sun ◽  
Zhutie Li ◽  
Junfeng Zhao ◽  
Xinxiang Yu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Metallic Glass ◽  
Electrical Discharge ◽  
Al Alloys ◽  
Micro Hardness ◽  
Discharge Treatment ◽  
Pulsed Electrical Discharge

Surface vitrification of alloys by pulsed electrical discharge treatment

2017 ◽  
Vol 707 ◽  
pp. 148-154 ◽  
Author(s):  
Lei Zuo ◽  
Shujie Pang ◽  
Shanfang Zou ◽  
Haifei Li ◽  
Tao Zhang
Keyword(s):  
Electrical Discharge ◽  
Discharge Treatment ◽  
Pulsed Electrical Discharge

scholarly journals About the Surface Hardening of Tool Steels by Electrical Discharge Treatment in Electrolyte

2010 ◽  
Vol 159 ◽  
pp. 137-140 ◽  
Author(s):  
Dimitar Krastev ◽  
Boyan Yordanov
Keyword(s):  
Corrosion Resistance ◽  
Metal Matrix ◽  
Electrical Discharge ◽  
Surface Hardening ◽  
High Speed ◽  
High Speed Steel ◽  
Metallic Surface ◽  
Tool Steels ◽  
Discharge Treatment ◽  
Nonequilibrium Phase Transformations

In this study are given some results about the influence of electrical discharge treatment in electrolyte on the microstructure of high speed steel HS 6-5-2. The metallic surface after electrical discharge treatment in electrolyte has a different structure in comparison with the metal matrix, which determines different properties. It is observed remarkable increasing of hardness, strength and corrosion resistance related to the nonequilibrium phase transformations and the obtained finecrystalline microstructure.

Effects of the Duration of Potentiostatic Anodizing on the Corrosion Resistance and Surface Morphology of Films Formed on Mg-Al Alloys

2005 ◽  
Vol 486-487 ◽  
pp. 125-128 ◽  
Author(s):  
Seong Jong Kim ◽  
Seok Ki Jang ◽  
Jeong Il Kim
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Anodic Oxide ◽  
Al Alloys ◽  
Anodic Film ◽  
Al Alloy ◽  
Active Dissolution ◽  
Dissolution Reaction ◽  
Alloy Az91 ◽  
Morphology Of Films

The effects of the duration of potentiostatic anodizing on the corrosion resistance and surface morphology of anodic oxide films formed on Mg-Al alloy (AZ91) in 1 M NaOH were investigated. With the formation of an anodic film, the current density decreased gradually, started to stabilize at 300 s, and was relatively constant at 600 s. These results may be related to the increased time for catalysis of the active dissolution reaction, which not only enlarges the area covered by the anodic film, but also produces a more coherent, thicker film. The reference corrosion potentials of the anodic oxide film for AZ91 shifted in the noble direction with time. In general, the corrosion resistance characteristics were improved with anodizing time.

MORPHOLOGICAL, MICRO-MECHANICAL, CORROSION AND IN VITRO BIOACTIVITY INVESTIGATION OF SUPERFICIAL LAYER FORMATION DURING WIRE ELECTRICAL DISCHARGE MACHINING OF Ti-6Al-4V ALLOY FOR BIOMEDICAL APPLICATION

2021 ◽  
Author(s):  
SANDEEP MALIK ◽  
VINEET KUMAR
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Biomedical Application ◽  
Superficial Layer ◽  
Pulse Interval ◽  
In Vitro Bioactivity ◽  
Nano Indentation

In this work, the experimental investigation of the surface integrity and biomechanical properties of the superficial layer obtained by wire electrical discharge machining (W-EDM) of Ti-6Al-4V alloy for biomedical application has been carried out. The surface morphology and elemental composition of the superficial layer have been investigated by field-emission scanning electron microscope (FE-SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. The micro-mechanical behavior in terms of compressive strength and surface hardness was studied using the micro-pillar and nano-indentation technique. The corrosion resistance and in vitro bioactivity have been investigated using electrochemical and immersion test. Morphological analysis showed that surface morphology and superficial layer thickness were affected by peak current, pulse-duration and pulse-interval. The niobium (Nb)-rich layer was developed in superficial layer zone. The low peak current (3–6[Formula: see text]A), low pulse-duration (5–10[Formula: see text][Formula: see text]s) and high pulse-interval ([Formula: see text]s) have been recommended for better surface morphology and thin superficial layer (ranging from 4–6[Formula: see text][Formula: see text]m) free from surface defects. The micro-pillar and nano-indentation results showed that the superficial layer comprised of a brittle structure that improved the mechanical properties of the layer and the compressive strength was measured to be 1198 MPa. The corrosion resistance analysis revealed that the Nb-rich layer in the superficial layer improved the corrosion resistance and bioactivity. Excellent apatite growth has been found in the W-EDM-processed zone. The W-EDM can be used for the biomedical industry as a potential surface engineering technique.

Plasma Surface Treatment: Effects on Mechanical and Corrosion Protection Properties of Hybrid Sol–Gel Coatings

2019 ◽  
Author(s):  
R. Subasri
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Surface Treatment ◽  
Corrosion Protection ◽  
Sol Gel ◽  
Surface Cleaning ◽  
Al Alloys ◽  
Plasma Surface ◽  
Wet Chemical ◽  
Pre Treatment

Surface cleaning and activation of substrates are two critical processes that affect the mechanical and corrosion resistance properties of protective coatings when deposited on the substrates. Surface cleaning removes the contaminants, for example, grease on the substrate, and surface activation introduces active bonds on the substrate thereby increasing the surface free energy. Conventionally, surface cleaning and activation of aluminum and its alloys are carried out by a wet chemical technique. A convenient and safe alternate to the wet chemical cleaning/activation would be to use plasma for the same purpose. Plasma surface pre-treatment greatly improves adhesion of coatings deposited, which is very vital for good corrosion protection and mechanical properties such as scratch and abrasion resistance. Cold and atmospheric air plasma treatments have been the most widely studied pre-treatments for Al alloys. This article will discuss the advancements in the use of plasma treatment on Al/Al alloys and its effect on corrosion resistance and mechanical properties of coatings deposited after the surface treatment.

scholarly journals Effect of Heat Treatment and Sulfuric Acid Anodization on Corrosion Resistance of Aluminum Alloy (AA7075)

2021 ◽  
Vol 40 (1) ◽  
pp. 56-62
Author(s):  
M. Abdullahi ◽  
L.S. Kuburi ◽  
P.T. Zubairu ◽  
U. Jabo ◽  
A.A. Yahaya ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Polarization Resistance ◽  
Testing Machine ◽  
Palm Kernel ◽  
Engine Oil ◽  
Micro Hardness

This paper, studied the effect of heat treatment and anodization on corrosion resistance of aluminum alloy 7075 (AA7075), with a view to improving its corrosion resistance. Microstructure and micro hardness of the anodic film of the samples were studied with the aid of optical metallurgical microscope and automated micro hardness testing machine. Linear polarization methods were used to assess the corrosion behaviour of the alloy in 0.5M HCl. The microstructure of the annealed sample showed formation of dendrites while precipitation hardened samples in palm kernel oil and SAE 40 engine oil showed precipitates of MgZn2. The SEMS result showed pores and micro cracks on the surfaces of the anodized samples, with the as cast and anodized sample in sulfuric acid exhibiting most compact with few pores. The as cast and sulfuric acid anodized sample shows highest micro hardness value of 205.33 HV, while the least value of 150.67 HV was recorded in sample precipitation hardened in SAE 40 engine oil and anodized in sulfuric acid. Analysis of the potentiodynamic polarization data and curves showed a linear relationship (decrease in icorr, decreases the corrosion rate) between current density and the corrosion rate in all the samples. Higher polarization resistance of 15.093 Ω/cm2 was recorded by the as cast and Sulfuric acid (SA) anodized sample while the precipitation treated in SAE 40 engine oil plus SA anodized sample recorded lowest polarization resistance of 5.2311 Ω/cm2. Heat treatment alone improves corrosion resistance of AA 7075 in 0.5 M HCl solution but heat treatment plus SA anodization does not improve corrosion resistance in the same environment.

scholarly journals Detection and removal of impurities in nitric oxide generated from air by pulsed electrical discharge

Nitric Oxide ◽  
2016 ◽  
Vol 60 ◽  
pp. 16-23 ◽  
Author(s):  
Binglan Yu ◽  
Aron H. Blaesi ◽  
Noel Casey ◽  
Grigory Raykhtsaum ◽  
Luca Zazzeron ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Electrical Discharge ◽  
Removal Of Impurities ◽  
Pulsed Electrical Discharge
Sign in / Sign up

Export Citation Format

Share Document