Inhomogeneous dealloying kinetics along grain boundaries during liquid metal dealloying

2022 ◽  
Vol 106 ◽  
pp. 41-48
Author(s):  
S.-H. Joo ◽  
Y.B. Jeong ◽  
T. Wada ◽  
I.V. Okulov ◽  
H. Kato
Keyword(s):  
Liquid Metal ◽  
Grain Boundaries

Forging of Copper and Iron Plates by the Damascus Technique

2019 ◽  
Vol 809 ◽  
pp. 253-258
Author(s):  
Susanne Strobl ◽  
Wolfgang Scheiblechner ◽  
Roland Haubner
Keyword(s):  
Composite Material ◽  
Melting Point ◽  
Liquid Metal ◽  
Grain Boundaries ◽  
Diffusion Zone ◽  
Copper Alloys ◽  
Layered Composite ◽  
Damascus Steel ◽  
Small Diffusion ◽  
Steel Grades

Forging of different steel grades is called Damascus technique and results in a layered composite material termed “Damascus steel”, but forging of different copper alloys is termed “mokume gane”. In this paper the joining of copper and iron plates by forging is described. Metallographic investigations showed well bonded interfaces of copper and iron. A very small diffusion zone was observed. To study the diffusion between copper and iron two heat treatments were performed in Ar atmosphere. After 30 minutes at 1000 °C a marginal Cu-Fe interaction took place. Above the melting point of Cu at 1100 °C an intense Cu-Fe interaction was observed, which significantly changes the interface of both metals. Cu penetrated Fe along the grain boundaries and Fe droplets were formed sporadically. This correlates with the typical morphologies of liquid metal embrittlement (LME). Moreover, Fe is dissolved in Cu at 1100 °C and after cooling fine Fe precipitates in the Cu phase were detected.

Grain Boundary Complexion Transitions

2020 ◽  
Vol 50 (1) ◽  
pp. 465-492 ◽  
Author(s):  
Patrick R. Cantwell ◽  
Timofey Frolov ◽  
Timothy J. Rupert ◽  
Amanda R. Krause ◽  
Christopher J. Marvel ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Bulk Composition ◽  
Polycrystalline Metals ◽  
Research Challenges ◽  
Rapid Changes ◽  
And Performance ◽  
Property Changes ◽  
Processing Properties

Grain boundaries can undergo phase-like transitions, called complexion transitions, in which their structure, composition, and properties change discontinuously as temperature, bulk composition, and other parameters are varied. Grain boundary complexion transitions can lead to rapid changes in the macroscopic properties of polycrystalline metals and ceramics and are responsible for a variety of materials phenomena as diverse as activated sintering and liquid-metal embrittlement. The property changes caused by grain boundary complexion transitions can be beneficial or detrimental. Grain boundary complexion engineering exploits beneficial complexion transitions to improve the processing, properties, and performance of materials. Here, we review the thermodynamic fundamentals of grain boundary complexion transitions, highlight the strongest experimental and computationalevidence for these transitions, clarify a number of important misconceptions, discuss the advantages of grain boundary complexion engineering, and summarize existing research challenges.

Liquid-Metal Wetting at Grain Boundaries: a Synchrotron-Micro-Radiographic Investigation

2003 ◽  
Vol 216-217 ◽  
pp. 241-248 ◽  
Author(s):  
E. Pereiro-López ◽  
Wolfgang Ludwig ◽  
Daniel Bellet ◽  
J. Baruchel
Keyword(s):  
Liquid Metal ◽  
Grain Boundaries ◽  
Radiographic Investigation

scholarly journals Effect of Silicon and Retained Austenite on the Liquid Metal Embrittlement Cracking Behavior of GEN3 and High-Strength Automotive Steels

2019 ◽  
Vol 98 (12) ◽  
pp. 351s-364s ◽  
Author(s):  
MURALI TUMULURU ◽  
Keyword(s):  
Liquid Metal ◽  
Grain Boundaries ◽  
Resistance Spot Welding ◽  
Retained Austenite ◽  
Spot Welding ◽  
Liquid Metal Embrittlement ◽  
Trip Effect ◽  
Cracking Behavior ◽  
Resistance Spot

GEN3 steels are a new family of automotive sheet steels developed and commercialized in the last three years, specifically for body-in-white applications. The high ductility in GEN3 steels is typically achieved through the transformation-induced plasticity (TRIP) effect by the addition of silicon or aluminum. When these steels are formed into parts, the TRIP effect of austenite to martensite transformation provides enhanced ductility. Typically, 10 to 12 micrometers of zinc coating (known as galvanized coating) is applied to automotive steel sheets for corrosion protection. Liquid metal embrittlement (LME) cracking can occur during resistance spot welding (RSW) of galvanized steels. LME cracking occurs when molten zinc penetrates prior austenite grain boundaries of the steel substrate. The precise role of silicon in the LME cracking behavior in TRIP and GEN3 steels is unknown. Therefore, a study was undertaken to examine the role of silicon in LME cracking behavior of GEN3 steels. The purpose was also to examine if the presence of retained austenite is required for LME cracking to occur. In this study, laboratory heats were prepared using three silicon levels. Samples cut from galvanized panels were welded using a resistance spot welding machine, and weld areas were examined metallographically for the presence of LME cracks. Gleeble® simulations were done to study the LME behavior of the three steels prepared. Base materials were examined with a scanning electron microscope using the electron back-scattered diffraction (EBSD) method to examine the nature of grain boundaries found. The effect of retained austenite in LME cracking was studied using the Gleeble®. Both RSW and Gleeble® results showed silicon promotes LME cracking in steels, predominantly in the weld heat-affected zones(HAZs). More low-energy, low-coincidence site lattice (CSL) boundaries were found as the silicon content of the steel was decreased. These boundaries do not host cracks. Higher silicon appeared to shrink the safe temperature range over which LME cracks could be avoided, thus indicating heat in-put control to limit cracks has limited windows as the silicon in steel goes up. It was shown that the presence of retained austenite in steel is not a prerequisite for LME cracking to occur.

scholarly journals Influence of Dysprosium Compounds on the Extraction Behavior of Dy from Nd-Dy-Fe-B Magnet Using Liquid Magnesium

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1345
Author(s):  
Sun-Woo Nam ◽  
Sang-Min Park ◽  
Mohammad Zarar Rasheed ◽  
Myung-Suk Song ◽  
Do-Hyang Kim ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Grain Boundaries ◽  
Microstructural Analysis ◽  
Metal Extraction ◽  
Phase Decomposition ◽  
Extraction Percentage ◽  
Extraction Behavior ◽  
Extraction Reaction ◽  
The Matrix ◽  
Phase Proceeds

During the liquid metal extraction reaction between a Nd-Dy-Fe-B magnet and liquid Mg, Nd rapidly diffuses out of the magnet, whereas Dy is not extracted due to the reaction with the matrix and the formation of Dy2Fe17 phase. In addition, theDy2O3 phase exists at the grain boundaries. Until now, only the effect of the Dy2O3 phase on the extraction of Dy has been reported. In this study, the effect of the Dy2Fe17 phase on the extraction of Dy from the Nd-Dy-Fe-B magnet was investigated in liquid Mg. The formation of the Dy2Fe17 phase during the reaction between Mg and matrix (RE2Fe14B) was first examined using a thermodynamical approach and confirmed by microstructural analysis. It was observed that Dy extraction was dominated by Dy2Fe17 phase decomposition from 3 h to 24 h, followed by Dy2O3 phase dominant reaction with Mg. Comparing the activities of the Dy2Fe17 phase and the Dy2O3 phase, the reaction of Dy2Fe17 is dominant, as compared to the Dy2O3 phase. Finally, at 48 h, the high Dy extraction percentage of 93% was achieved. As a result, in was concluded that the Dy2Fe17 phase acts as an obstacle in the extraction of Dy. In the future, if research to control the Dy2Fe17 phase proceeds, it will be of great importance to advance the recycling of Dy.

Liquid metal penetration at grain boundaries: Characterization by synchrotron radiation micro-radiography and micro-fluorescence

2002 ◽  
Vol 12 (8) ◽  
pp. 289-298 ◽  
Author(s):  
W. Ludwig ◽  
D. Bellet ◽  
J. Teyssier ◽  
J. Ouillier ◽  
N. Marie ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Liquid Metal ◽  
Grain Boundaries
Sign in / Sign up

Export Citation Format

Share Document