Nucleation and Ostwald Growth of Particles in Fe-O-Al-Ca Melt

Abstract

Tremendous focus has been put on the control of particle size distribution which effects the grain structure and mechanical properties of resulting metallic materials, and thus nucleation and growth of particles in solution should be clarified. This study uses classical nucleation theory and Ostwald ripening theory to probe the relationship between the compositions of Fe-O-Al-Ca melts and the behavior of particles under the condition of no external stirring. Our experimental data suggest that decreasing the initial Ca addition and Al addition is conductive to the increase of nucleation rate for calcium aluminate particles, which exhibits a same change trend with that predicted from classical nucleation theory. Based on the experimental evidence for particles size distribution in three-dimensional, we demonstrate that Ostwald ripening is the predominate mechanism on the coarsening of particles in Fe-O-Al-Ca melt at early stage of deoxidation under the condition of no external stirring but not at later stage.

Coarsening Behavior of Particles in Fe-O-Al-Ca Melts

“…In their study, Ostwald ripening dominates the growth of particles in deoxidation process under no fluid flow. However, in our previous study 36 , the experimental evidence for particles size distribution in Fe-O-Al-Ca melt corresponds to the theoretical results based on Ostwald ripening at early stage of deoxidation but not at later stage. Therefore, it is necessary to study the change of particle size distribution in liquid metal affected by the collision and subsequent coagulation.…”

A catalogue of cancer-driving mutations in healthy tissue

“…For example, one area that would be worth studying is whether long-term use of pain-blocking opioid drugs, such as morphine, might affect nociceptor-mediated antibacterial defence. This is of interest because nociceptors are the main target of opioids, and administering morphine to mice changes the gut's microbial composition 15,16 . Moreover, morphine use promotes the spread of certain types of microbe (Gram-negative bacteria) from the gut to elsewhere in the body, a process that can lead to sepsis, a potentially life-threatening immune response to infection 15,16 .…”

“…This is of interest because nociceptors are the main target of opioids, and administering morphine to mice changes the gut's microbial composition 15,16 . Moreover, morphine use promotes the spread of certain types of microbe (Gram-negative bacteria) from the gut to elsewhere in the body, a process that can lead to sepsis, a potentially life-threatening immune response to infection 15,16 . Future research that explores interactions between neurons and immune cells during infection could uncover further exciting findings that will profoundly influence our understanding of host defence.…”

Inclusion Characteristics in 95CrMo Steels with Different Calcium and Sulfur Contents

“…The two-dimensional inclusion size distribution was transformed into three-dimensional inclusion size distribution based on stereological analysis (modified Schwartz-Saltykov method with the probability mass function [35,36]), which was applied in the estimation of the volume fraction inclusions in Equation (2), and the details are similar to our previous research [11,37]. The contents of Al, Ca, Mg, Si, Mn, O, and S in inclusions were detected by point EDS analysis in the center of each inclusion and they were transformed into their respective compound based on their stoichiometric relationship.…”

“…There are extensive researches on the formation mechanism and evolution of calcium aluminates [6][7][8][9][10][11]. Many studies were focused on the kinetic calculation of inclusions during calcium treatment [6,12].…”