The low W/W and high He/He in some ocean island basalts compared to the bulk mantle values may derive from the Earth's core through long-term core-mantle interactions. It has been proposed that the grain boundary diffusion of siderophile elements is an efficient mechanism for core-mantle interaction and may effectively modify the W isotopic compositions of the plume-source mantle. In this study, we perform large-scale molecular dynamics simulations driven by machine learning potentials of ab initio quality to investigate the diffusion of W along ferropericlase grain boundaries and in (Mg,Fe)O liquid. Here we show that the diffusion of W is sluggish under core-mantle boundary conditions, and thus is unlikely to have observable impacts on the W isotopic compositions of terrestrial igneous rocks.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11845664 | PMC |
http://dx.doi.org/10.1038/s41467-025-57120-1 | DOI Listing |
ACS Appl Nano Mater
March 2025
Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States.
We report a fast and straightforward preparation of centimeter-sized Cu(111) from polycrystalline Cu foil by the strain-free abnormal grain growth method and the subsequent growth of monolayer graphene by chemical vapor deposition (CVD). The fabrication of Cu(111) and graphene was streamlined into a straightforward process using a CVD system consisting of a tube furnace and a quartz boat. It was found that the annealing temperature and time are critical in the growth of Cu(111).
View Article and Find Full Text PDFMaterials (Basel)
March 2025
The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China.
In order to find the optimal heat input for simulating the welding of the coarse-grained heat-affected zone (CGHAZ) of a novel Q690 MPa V-N microalloyed medium and heavy plate, the study investigated the precipitation of V (C, N), microstructural changes, and impact toughness under five different heat inputs (E). The results show that in the CGHAZ, as the heat input increases, the dominant microstructure changes from intragranular acicular ferrite (IGAF) and lath bainitic ferrite (LBF) to polygonal ferrite (PF) and a small amount of IGAF. At the same time, the area fraction of the brittle phase martensite/austenite (M/A) constituents increased from 4.
View Article and Find Full Text PDFMaterials (Basel)
February 2025
Romanian Research and Development Institute for Gas Turbines COMOTI, 220D Iuliu Maniu Av., 061126 Bucharest, Romania.
The present study was focused on assessing the molten salt-induced hot corrosion resistance of selective laser melting (SLM) manufactured Inconel 625 at 900 °C for 96 h and investigating the possibility of improving the superalloy's corrosion resistance by applying a pre-oxidation heat treatment. The material's hot corrosion properties were assessed in a heat-treated state (heat treatments performed at 1000 °C/1 h and 1150 °C/1 h, respectively) with and without pre-oxidation. The heat treatment at 1000 °C promoted the columnar dendrite morphology evolution, while the heat treatment at 1150 °C promoted the equiaxed dendrite morphology evolution.
View Article and Find Full Text PDFMaterials (Basel)
February 2025
Virtual Materials Laboratory, School of Materials Science and Engineering, Engineering Research Institute, Gyeongsang National University, Jinju 52828, Republic of Korea.
The heat treatment process of Ti-6Al-4V alloy alters its microstructural features such as prior-β grain size, Widmanstatten α lath thickness, Widmanstatten α volume fraction, grain boundary α lath thickness, total α volume fraction, α colony size, and α platelet length. These microstructural features affect the material's mechanical properties (UTS, YS, and %EL). The relationship between microstructural features and mechanical properties is very complex and non-linear.
View Article and Find Full Text PDFMaterials (Basel)
February 2025
Central Iron and Steel Research Institute Co., Ltd., Beijing 100081, China.
In this work, we aimed to study the austenite grain growth behavior of an ultra-high-strength stainless steel within the temperature range of 900-1150 °C and holding time range of 0-120 min, using a metallographic microscope and metallographic image analysis software to perform a statistical analysis of grain size variation. The undissolved phases of the steel were investigated using a field emission scanning electron microscope (SEM) and transmission electron microscope (TEM). Within the temperature range of 900-950 °C, the grain growth rate of the steel was slow, while within the range of 1000-1150 °C, the grain growth rate was relatively fast.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!