Mechanical alloying (MA) is a solid-state powder processng technique involving repeated welding, fracturing, and rewelding of powder particles in a high-energy ball mill. Originally developed to produce oxide-dispersion strengthened (ODS) nickel- and iron-base superalloys for applications in the aerospace industry, MA has now been shown to be capable of synthesizing a variety of equilibrium and non-equilibrium alloy phases starting from blended elemental or prealloyed powders. The non-equilibrium phases synthesized include supersaturated solid solutions, metastable crystalline and quasicrystalline phases, nanostructures, and amorphous alloys. Recent advances in these areas and also on disordering of ordered intermetallics and mechanochemical synthesis of materials have been critically reviewed after discussing the process and process variables involved in MA. The often vexing problem of powder contamination has been analyzed and methods have been suggested to avoid/minimize it. The present understanding of the modeling of the MA process has also been discussed. The present and potential applications of MA are described. Wherever possible, comparisons have been made on the product phases obtained by MA with those of rapid solidification processing, another non-equilibrium processing technique.

Mechanical Alloying And Milling

This manuscript explores the influence of atomic structure on glass forming ability and thermal stability in binary metallic glasses. A critical assessment gives literature data for 628 alloys from 175 binary glass systems. The atomic structure is quantified for each alloy using the efficient cluster packing model. Comparison of atomic structure with amorphous thickness and thermal stability gives the following major results. Binary glasses show a strong preference for discrete solute to solvent atomic radius ratios R*, which give efficient local atomic packing. Of 15 possible R* values, only five are common and only four represent the most stable glasses. The most stable binary glasses are also typically solute rich, with enough solute atoms to fill all the solute sites and roughly one-third of the solvent sites. This suggests that antisite defects, where solutes occupy solvent atom sites, are important in the glass forming ability of the most stable glasses. This stabilising effect resul...

An assessment of binary metallic glasses: correlations between structure, glass forming ability and stability

Amorphous metallic powders can be formed by mechanical alloying in a high energy ball mill Starting from the elemental, crystalline powders, ball milling first produces powder particles with a characteristically layered microstructure Further milling leads to an ultrafine composite in which amorphization by solid state reaction takes place A study of the influence of the milling intensity on glass formation shows that the effective temperature during mechanical alloying can rise significantly In addition to the use of X-ray diffraction and differential scanning calorimetry to study crystallization the atomic arrangement can be characterized by the measurement of structure-sensitive physical properties such as superconductivity, Mossbauer effect, structural relaxation and hydrogen absorption As a result, the atomic structure of the mechanically alloyed amorphous metals is quite similar to that of melt-spun samples showing that the amorphous state should not be considered a frozen liquid but a metastable phase which can be equally approached by quenching from the liquid state and by a crystal-glass transition via interdiffusion The glass-forming ranges for mechanical alloying can also be exactly determined by measuring physical properties as a function of composition These experimentally obtained glass-forming ranges agree quite well with those derived theoretically, indicating that glass formation by mechanical alloying can be described as a metastable equilibrium process neglecting the existence of intermetallic phases which are prevented from formation by the kinetic restrictions of the mechanical alloying process

Glass formation by mechanical alloying

We present a crystallization study of melt‐spun Fe‐Zr metallic glasses. Unlike Cu‐Zr and Ni‐Zr, the immediate crystallization products cannot be understood in terms of the equilibrium crystalline phase diagram: all are metastable or unstable phases. In the composition range Fe25Zr75 to Fe33Zr67, there is evidence that explosive crystallization occurs. The behavior of the activation energy with composition suggests there may be a eutectic at the composition Fe37.5Zr62.5.

Crystallization characteristics of Fe‐Zr metallic glasses from Fe43Zr57 to Fe20Zr80

The structure of the product in mechanical alloying depends both on the elemental composition and the milling conditions. An increase of ball energy led to more pronounced crystallinity of the product. Mechanical alloying at small ball energy leads to the formation of amorphous alloys for Zr-Co and Cu-Ti systems. Demixing of Ti3Cu4 into crystalline TiCu and TiCu4 and demixing of Zr50Co50 into Zr3Co and ZrCo2 was found. The results are explained on the basis of the concept of tribochemical equilibrium.

http://www.crystallography.ru/MA/articles/Gerasimov1991.pdf

Tribochemical equilibrium in mechanical alloying of metals

Structure analyses of amorphous melt-spun FeZr(B, Si) alloys and mechanically alloyed FeZr powders☆

Amorphous Zr-rich Zr100-xMx alloys were prepared in the composition range 20≤x(Fe)≤35, 22≤x(Co)≤54, 23≤x(Ni)≤64 for M = Fe, Co, Ni respectively. The structure of the amorphous ZrFe alloys was determined by X-ray diffraction and Mossbauer-effect measurements, which indicate a deviation of the atomic arrangements in these metallic glasses from the DRPHS model. The crystallization processes were investigated by a combined analysis of DSC, resistivity, TEM, X-ray and Mossbauer-effect measurements. In the ZrFe system, crystallization of α-Zr as well as ω-Zr and cubic Zr2Fe ( a = 12.2 A ) was observed in the temperature region between 350 and 450° C, followed by a transformation into orthorhombic Zr3Fe which leads to an additional small exothermal peak in the DSC scan. First results of a comparative analysis of the three systems are discussed.

Structure and crystallization of amorphous Zr100-xMx alloys

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

C. Michaelsen

Author Tools

Chat about Author

Papers

Structure analyses of amorphous melt-spun FeZr(B, Si) alloys and mechanically alloyed FeZr powders☆

Structure and crystallization of amorphous Zr100-xMx alloys