The crystallization process of amorphous Al80Fe20 alloy powders prepared by ball milling
نویسندگان
چکیده
The amorphous-to-crystalline transition during thermal annealing of amorphous Al80Fe20 alloy powders prepared by ball milling was investigated by means of magnetothermal analysis and X-ray diraction. Following structural relaxation and stress relief processes, a metastable phase precipitates during primary crystallization, and a mixture of intermetallic compound (h-Al13Fe4) and fcc Al is developed further. On heating at constant rate annealing the ®rst and succeeding reactions overlap to some extent in temperature. The apparent activation energy for primary crystallization amounts to 1.99 0.10 eV by using the Kissinger method. In addition, the structure of the metastable phase, which has not been identi®ed yet, is brie ̄y discussed. Ó 1999 Elsevier Science B.V. All rights reserved.
منابع مشابه
Effect of Ni on Amorphization of Ti-Cu-Ni Ternary alloys Prepared by Mechanical alloying
Amorphous alloys has been taken into consideration because of their unique properties and are nominated as the future engineering materials. In this research, the effect of Ni and milling time on amorphization process and thermal stability of Ti50Cu50-xNix(x=10, 15, 25 at%) alloy system were investigated. The evolution of amorphization during milling, thermal stability and subsequent heat treat...
متن کاملFabrication of TiC particulate reinforced Ni-50Fe super alloy matrix composite powder by mechanical alloying
Mechanical alloying is a powder metallurgy processing technique involving cold welding, fracturing, and rewelding of powder particles in a high-energy ball mill. In this work, NiFe-TiC composite powders were prepared by mechanical alloying process using planetary high-energy ball mill. The effect of TiC addition by weight percent on the NiFe solid solution formation, grain size, lattice paramet...
متن کاملThe Influence of Heat Treatment and High Energy Ball Milling on the Density, Hardness, and Wear Behavior of Al 7150 Alloy via Hot Uniaxial Compaction
The effect of the milling time & ageing on the hardness, density, and wear characteristics of Al 7150 alloy specimens made via powder metallurgy has been studied. The different constituents of Al 7150 alloy were processed in a planetary ball milling set up with a BPR of 10:1 for 5 hours, 10 hours, and 20 hours. At 400 °C, the milled powders were subsequently hot compacted in a punch die setup. ...
متن کاملبررسی تغییرات فازی سیلیس و سیلیسیوم به هنگام آسیاب کاری
In the present study phase transformation of silicon and silica during milling in different atmospheres was investigated. The silicon powder was subjected to high energy ball milling in ammonia (25%) atmosphere. The milled powder was subsequently annealed at 1200 ◦C for 1 hour. In another test a mixture of AlN and amorphous silica (micro silica) was subjected to high energy ball milling. The m...
متن کاملFormation of glassy Ti50Cu20Ni24Si4B2 alloy by high-energy ball milling
The elemental powder mixtures with a nominal composition of Ti50Cu20Ni24Si4B2 can be amorphized under high-energy ball milling. A well-defined glass transition before crystallization appears in the obtained amorphous phase during heating in a differential scanning calorimeter. Awide supercooled liquid region DTx is available to be about 57 K. Crystallization of the ballmilled amorphous phase wa...
متن کامل