J. Mater. Sci. Technol. ›› 1998, Vol. 14 ›› Issue (6): 491-496.

• Reviews • 上一篇    下一篇

Formation Mechanism of NiAl/TiB_2 Nanocomposite by Mechanical Alloying Elemental Powders

Lanzhang ZHOU and Jianting GUO(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China)   

  • 收稿日期:1998-11-28 修回日期:1998-11-28 出版日期:1998-11-28 发布日期:2009-10-10

Formation Mechanism of NiAl/TiB_2 Nanocomposite by Mechanical Alloying Elemental Powders

Lanzhang ZHOU and Jianting GUO(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China)   

  • Received:1998-11-28 Revised:1998-11-28 Online:1998-11-28 Published:2009-10-10

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摘要：

1.IntroductionTodaynanocrystallinematerialsreceivegreatin-terestbecauseoftheirnovelpropertiesl1~3l.Ofpar-ticularinterestisthepotentia.lthatthesenanos-tructurestransformnominallybrittlecompoundsilltoductilematerials[4~6].AproblemcommontonanocrystallinematerialsistheiriIilierentlackofther-malstabilityandthetendencyofgraingrowthdur-ingfurtherprocessing-Aneffectiveapproachtolimitgraingrowthistopr....

Abstract:

A NiAl/TiB2 nanocomposite is synthesized by mechanical alloying elemental powders. Upon milling for a certain time, an abrupt exothermic reaction occurs and a large amount of NiAl and TiB2 compounds form simultaneously. It is suggested that two separate chemical reactions,i.e. Ni+Al →NiAl and Ti+2B→TiB2, are involved during the exothermic reaction. Additionof Ti and B to Ni-Al system impedes the structural evolution of Ni and Al powders and delays the abrupt reaction. The final products are equilibrium phases without any metastable phases formed. This type of reaction is suggested to be suitable for alloy systems with two large heatrelease reactions.