Effect of Addition of Process Control Agent (PCA) on the Nanocrystalline Behavior of Elemental Silver during High Energy Milling

Abstract

Mechanical Alloying (MA) or High Energy Milling has been a subject of great interest for last few decades. However, in the majority of the cases the investigations are confined to areas like alloying in binary or multi-component systems from premixed powders. Very little work has been reported on high-energy milling of pure metals. There are some reports on mechanical alloying of pure metals that undergo polymorphic transformation on milling, but relatively few papers have been reported in the literature pertaining to attrition milling of pure metals, which do not fall under this category. One such attempt has been made in this investigation by subjecting a noble metal like silver with fcc crystal structure to attrition milling. The present work deals with the investigation of the effect of addition of a process control agent (PCA) on the nanocrystalline behavior of elemental silver powder subjected to high energy milling in an attritor. Elemental silver powder was subjected to attrition milling with and without addition of stearic acid as PCA. The powder samples drawn at periodic intervals during the course of milling were subjected to characterization using techniques like XRD, SEM and DSC. The variation in particle shape morphology, crystallite size and lattice strain as a function of PCA was studied.

PENGARUH WAKTU PEMADUAN BAGI TEKNIK PEMADUAN MEKANIK TERHADAP KEKERASAN PADUAN Al-10%beratTi

“…Dengan bertambahnya waktu pemaduan, puncak difraktogram bagi unsur aluminium dan titanium semakin bergeser ke kanan dan melebar seperti yang ditunjukkan dalam Gambar 3. Pelebaran puncak tersebut disebabkan oleh pengurangan ukuran partikel [13]. Puncak difraktogram untuk unsur titanium berangsur-angsur hilang dan menghilang ketika waktu pemaduan selama 30 jam (Gambar 2).…”

Regulating the work function of silver catalystsviasurface engineering for enhanced CO2electroreduction

“…As a typical mechanical technique, high-energy ball milling is a mechanical deformation process that is frequently used for producing metals with clean surfaces. Therefore, it can be used as a strategy to effectively regulate the ratio of exposed crystalline planes, 27,28 which enables us to explore the influence of the work function via regulating the ratio of exposed surfaces on electrocatalytic performance.…”

Contamination in wet-ball milling

“…This article surveys the presence, cause and effects of PCA-assisted contamination (particularly from hydrocarbons), so that the ball milling community is informed. While there is a plethora of dedicated case studies available on the effect of PCA on the grain size [5,6], atomic strains [6], solid solubility [7] and microstructural evolution [8] during ball milling [2], only a few [9,10,11] could be found, which can confirm PCA-induced contamination. No first-hand experimental data are presented here, instead a theory is proposed that explains contamination, and important literature works are reviewed in the context of explaining the effects of contamination.…”