scholarly journals The Effect of Microstructural Imperfections on Corrosion Fatigue of Additively Manufactured ER70S-6 Alloy Produced by Wire Arc Deposition

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 98 ◽  
Author(s):  
Tomer Ron ◽  
Galit Katarivas Levy ◽  
Ohad Dolev ◽  
Avi Leon ◽  
Amnon Shirizly ◽  
...  

This study aims at evaluating the effect of microstructure imperfections on the corrosion fatigue performance of an ER70S-6 alloy produced by wire arc additive manufacturing (WAAM) process, in a 3.5% NaCl solution. For reference, a regular ST-37 alloy with relatively similar chemical composition was considered as a counterpart alloy. This was justified by the fact that the ER70S-6 alloy is usually used for conventional welding of ST-37 steel. The results obtained indicated that while the ST-37 alloy exhibited fatigue strength of 240 MPa in the corrosive solution, the additively manufactured ER70S-6 alloy showed fatigue strength of only 140 MPa. These differences were related to microstructural imperfections that are inherently produced during the WAAM process.

2021 ◽  
Vol 118 (5) ◽  
pp. 502
Author(s):  
Jiarong Zhang ◽  
Xinjie Di ◽  
Chengning Li ◽  
Xipeng Zhao ◽  
Lingzhi Ba ◽  
...  

Functional graded materials (FGMs) have been widely applied in many engineering fields, and are very potential to be the substitutions of dissimilar metal welding joints due to their overall performance. In this work, the Inconel625-high-strength low-alloy (HSLA) Steel FGM was fabricated by wire arc additive manufacturing (WAAM). The chemical composition distribution, microstructure, phase evolution and mechanical properties of the FGM were examined. With the increasing of HSLA Steel, the chemical composition appeared graded distribution, and the primary dendrite spacing was largest in graded region with 20%HSLA Steel and then gradually decreased. And the main microstructure of the FGM transformed from columnar dendrites to equiaxed dendrites. Laves phase precipitated along dendrites boundary when the content of HSLA Steel was lower than 70% and Nb-rich carbides precipitated when the content of HSLA Steel exceeded to 70%. Microhardness and tensile strength gradually decreased with ascending content of HSLA Steel, and had a drastic improvement (159HV to 228HV and 355Mpa to 733Mpa) when proportion of HSLA Steel increased from 70% to 80%.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ruixin Mi ◽  
Z. Z. Shao ◽  
F. Vollrath

Abstract Demand for rhino horn is driving poaching with devastating effect for the few individuals left of the few species surviving from this once numerous, widespread and cosmopolitan clade of pachyderms. We bundled together tail hairs of the rhino’s ubiquitous near relative, the horse, to be glued together with a bespoke matrix of regenerated silk mimicking the collagenous component of the real horn. This approach allowed us to fabricate composite structures that were confusingly similar to real rhino horn in look, feel and properties. Spectral and thermal FT-IR, DSC and TGA analysis demonstrated the similar chemical composition and thermo-mechanical properties between the natural and the faux horns.


1986 ◽  
Vol 43 (2) ◽  
pp. 271-278 ◽  
Author(s):  
M. Ramanzin ◽  
E. R. Ørskov ◽  
A. K. Tuah

ABSTRACTTwo varieties of barley straw, Corgi and Gerbel, which varied in degradability when incubated in the rumen in nylon bags, were chosen for further examination of botanical fractions and to see how each fraction responded to treatment with ammonia. The straws were separated into leaves, internodes, nodes and chaff. The average proportions of these fractions were respectively 0·499, 0·380, 0·055 and 0·065 in Corgi straw and 0·404, 0·512, 0·059 and 0·025 in Gerbel straw. For both varieties the degradability of the botanical fractions were leaves > chaff > nodes > internodes.Despite a similar chemical composition, the dry-matter loss (DML) values of leaves, internodes and nodes of Corgi were higher than those of Gerbel straw.The differences between varieties were larger for internodes and nodes than for leaves. The difference in DML of the two varieties at 48-h incubation was 132 g/kg DM. Of this difference, 25 g were due to differences in distribution of the botanical fractions and 107 g to differences in DML of the fractions.Ammonia treatment significantly increased the DML of all fractions except the nodes. The overall improvement due to ammonia treatment of the different fraction was internode > chaff > leaves > nodes.


1929 ◽  
Vol 66 (3) ◽  
pp. 116-121
Author(s):  
S. J. Shand

In most systems of petrography the glassy rocks are treated in a very casual way. The names which are commonly given to them, such as obsidian, pitchstone, perlite, vitrophyre, and the like, afford no reliable indication of composition; and when a rock is partly crystalline and partly glassy, the composition of the glass is often assumed, quite unwarrantably, to be the same as that of the crystals. It is only in the Norm classification that vitreous rocks fall unfailingly into the same compartments as holocrystalline ones of similar chemical composition; and before any rock can be classified by this method, it is necessary to have a complete chemical analysis of it; which is, for many workers, a serious obstacle.


2014 ◽  
Vol 12 (2) ◽  
pp. 183-194
Author(s):  
Snezana Kalamkovic ◽  
Tibor Halasi

This paper describes the archaeological sites Mediana and Naisus during Late Antiquity. Microscopic images of bricks, and the results and analysis of XRF bricks from these archaeological sites are shown. Based on the results, it can be concluded that a similar brick exterior, and approximately the same chemical composition. One reason is, most likely, a similar chemical composition of the soil, because the archaeological sites are geographically close to each other. Another reason could be the same way bricks were producted, and that the same fuel was used in the kilns.


2020 ◽  
Vol 198 ◽  
pp. 01022
Author(s):  
Yuheng Dai ◽  
Jianxun Ma ◽  
Chen Guo ◽  
Xin Xu

Magnesium slag is a kind of industrial waste with the similar chemical composition to silicate cements, which is of hydration activity to some extent. However, the hydration activity of magnesium slag is much lower than that of traditional silicate cements. Through the method of carbonization, this experiment enhanced the hydration activity of magnesium slag, so that the strength of magnesium slag products can meet the requirements of structures together with certain mechanical and physical properties as well.


Author(s):  
Aziz Amjadi ◽  
D. Chomko

Ground waters of Shyraz Intermountain Trough are widely used for water-supply, watering crops, in industry, and for other purposes. It is currently being planned to make extensive use of ground waters of the Horamabad Trough. Discriminating large areas of ground waters of similar chemical composition and compounds containing over 10 elements is becoming a challenging task. Chemical composition of ground waters results from a number of natural and anthropogenic processes, which affect both interchange of chemical components and the nature of their bonds. However, these bonds do not remain unaffected, and are, virtually, the outcome of a number of processes. We offer a new method that is based on the use of cluster analysis, the application of which will make it possible to discriminate ground waters of similar chemical composition in different areas. This will enable both revealing similarities and differences in the processes of water supply and discharge, which define the chemical make-up of the ground waters, threats of pollution and depletion, and taking measures on ground water preservation. The method was tested on sampling chemical composition of ground waters of Shyraz and Horamabad Intermountain Troughs in Iran. Based on the cluster analysis data of the first matrix (Shyraz Intermountain Trough) and the second matrix (Horamabad Intermountain Trough) step-by-step diagrams of merging intervals are built, and dendrograms, namely. The claster analysis data being processed, the following conclusions can be made: 1. within Shyraz Intermountain Trough, there are discriminated three areas of ground waters bearing similar chemical composition in claster 1; two areas located in claster 2; three areas in claster 3; two areas in claster 4; and one area in claster 5; 2. within Horamabad Intermountain Trough, there are discriminated two areas of ground waters bearing similar chemical composition in claster 1; three areas located in claster 2; two areas in claster 3; four areas in claster 4; and per one area in clasters 5 and 6, correspondingly; 3. changes in ground water chemical composition in Shyraz and Horamabad Intermountain Troughs are interdependent; 4. the method mentioned can be used for chemical zoning of the ground waters.


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