Garai Mrinmoy, Reka Arianit A, Karmakar Basudeb, Molla Atiar R
Specialty Glass Division, CSIR-Central Glass & Ceramic Research Institute (CGCRI) Kolkata India
Department of Chemistry, Faculty of Natural Sciences and Mathematics, University of Tetova Blvd Ilinden n. n. 1200 Tetovo Republic of North Macedonia.
RSC Adv. 2021 Mar 18;11(19):11415-11424. doi: 10.1039/d0ra10519h. eCollection 2021 Mar 16.
In understanding the catalytic efficacy of silver (Ag) and gold (Au) nanoparticles (NPs) on glass-ceramic (GC) crystallization, the microstructure-machinability correlation of a SiO-MgO-AlO-BO-KO-MgF system is studied. The thermal parameters , glass transition temperature ( ) and crystallization temperature ( ) were extensively changed by varying NPs ( or ). Tc was found to be increased ( = 870-875 °C) by 90-110 °C when NPs were present in the glass system. Under controlled heat-treatment at 950 ± 10 °C, the glasses were converted into glass-ceramics with the predominant presence of crystalline phase (XRD) fluorophlogopite mica, [KMg(AlSiO)F]. Along with the secondary phase enstatite (MgSiO), the presence of Ag and Au particles (FCC system) were identified by XRD. A microstructure containing spherical crystallite precipitates (∼50-400 nm) has been observed through FESEM in doped GCs. An Ag doped GC matrix composed of rock-like and plate-like crystallites mostly of size 1-3 μm ensured its superior machinability. Vicker's and Knoop microhardness of doped GCs were estimated within the range 4.45-4.61 GPa which is reduced to 4.21-4.34 GPa in the Ag system. Machinability of GCs was found to be in the order, Ag > Au ∼ Ag > Au. Thus, the Ag/Au doped SiO-MgO-AlO-BO-KO-MgF GC has potential for use as a machinable glass-ceramic.
在理解银（Ag）和金（Au）纳米颗粒（NPs）对微晶玻璃（GC）结晶的催化效果时，研究了SiO-MgO-AlO-BO-KO-MgF系统的微观结构与可加工性之间的相关性。通过改变纳米颗粒（Ag或Au），热参数、玻璃化转变温度（Tg）和结晶温度（Tc）发生了显著变化。当玻璃体系中存在Au纳米颗粒时，发现Tc升高（从870 - 875°C）了90 - 110°C。在950±10°C的控制热处理条件下，玻璃转变为主要含有晶相（XRD）氟金云母[KMg(AlSiO)F]的微晶玻璃。除了次生相顽火辉石（MgSiO）外，通过XRD还鉴定出了Ag和Au颗粒（FCC体系）的存在。通过FESEM在Au掺杂的微晶玻璃中观察到了包含球形微晶沉淀（约50 - 400 nm）的微观结构。由尺寸大多为1 - 3μm的岩石状和板状微晶组成的Ag掺杂GC基体确保了其优异的可加工性。Au掺杂的微晶玻璃的维氏硬度和努氏硬度估计在4.45 - 4.61 GPa范围内，而在Ag体系中则降至4.21 - 4.34 GPa。发现微晶玻璃的可加工性顺序为：Ag > Au ∼ Ag > Au。因此，Ag/Au掺杂的SiO-MgO-AlO-BO-KO-MgF微晶玻璃具有用作可加工微晶玻璃的潜力。
