Thermal Stability of Graphite/Copper Nanocrystalline Composite Powders Prepared by High Energy Mechanical Milling

Jin, Yong Ping; Hu, Ming

doi:10.4028/www.scientific.net/AMR.217-218.941

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Thermal Stability of Graphite/Copper Nanocrystalline Composite Powders Prepared by High Energy Mechanical Milling

Abstract:

To provide reference for choosing technological parameters of subsequent powder densification, thermal stability of 3 h-milled 3 wt% graphite/copper nanocrystalline composite powders were investigated with such analytical methods as scanning electron microscopy (SEM), back-scattered electron images and X-ray diffraction (XRD). The results show that diffraction peak of graphite in XRD pattern is absent because of too small graphite particle. No major variation of grain size of Cu with annealing temperature is observed. Accumulation and growth of graphite phase aren’t seen. The microhardness is nearly constant for the annealed powders. Therefore, 3 h-milled 3 wt% graphite/copper nanocrystalline composite powders possess good thermal stability.

Info:

Periodical:

Advanced Materials Research (Volumes 217-218)

Main Theme:

High Performance Structures and Materials Engineering

Edited by:

Zhou Mark

Pages:

941-945

DOI:

https://doi.org/10.4028/www.scientific.net/AMR.217-218.941

Citation:

Y. P. Jin and M. Hu, "Thermal Stability of Graphite/Copper Nanocrystalline Composite Powders Prepared by High Energy Mechanical Milling", Advanced Materials Research, Vols. 217-218, pp. 941-945, 2011

Online since:

March 2011

Authors:

Yong Ping Jin, Ming Hu

Keywords:

Graphite/Copper Nanocrystalline Composite Powder, High Energy Mechanical Milling, Thermal Stability

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References

[1] X. S. Liu: Research and application of contact materials (National Defence Industry Press, Beijing 1979), in Chinese.

[2] K. Okada and M. Yoshida: Proceedings of the 37th IEEE Holm Conference on Electrical Contacts, (1991), p.149~152.

[3] F. F. O. Orumwense: Metal Powder Report Vol. 57(2002), p.85.

[4] S. Y. Chang, C. F. Chen, S. J. Lin, et al: Acta Materialia Vol. 51(2003), p.6291~6302.

[5] C. Suryanara: Prog. Mater. Sci. Vol. 46(2001), p.1~84.

[6] M. Atzmon, J. Xu and H. H. Tian: Mater. Sci. Forum Vol. 360-362(2000), p.311~316.

[7] B. S. Murty and S. Ranganathan: Int. Mater. Rev. Vol. 43(1998), p.1~141.

[8] Y. P. Jin, B. Guo and E. D. Wang: The Chinese Journal of Nonferrous Metals Vol. 17(2007), p.1490~1494, in Chinese.

[9] Y. P. Jin, B. Guo and E. D. Wang: Materials Science & Technology Vol. 16(2008), p.704~707, in Chinese.

[10] M. T. Marques, J. B. Correia and O. Conde: Scripta Materialia Vol. 50(2004), p.963~967.

Paper TitlePages

Synthesis of TiFe Compound from Ball Milled TiH₂ and Fe Powders Mixtures

Authors: Railson Bolsoni Falcão, Edgar Djalma Campos Carneiro Dammann, Cláudio José da Rocha, Rodrigo Uchida Ichikawa, Michelangelo Durazzo, Luís Gallego Martinez, Ricardo Mendes Leal Neto

Abstract: TiFe compound was produced by high-energy ball milling of TiH₂ and Fe powders, followed by heating under vacuum. TiH₂ was used instead of Ti in order to avoid the strong particles adhesion to grinding balls and vial walls. Mixtures of TiH₂ and Fe powders were dry-milled in a planetary mill for times ranging from 5 to 40 hours. The amount of sample, number and diameter of the balls were kept constant in all experiments. After milling, samples were heated under dynamic high-vacuum for the synthesis reaction. As-milled and heat-treated materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). The mean crystallite sizes and microstrains were determined by XRD line profile analysis using the Warren-Averbach method. As-milled materials presented only Fe and TiH₂ phases. Nanostructured TiFe compound was formed after heat treatment. TiH₂ was effective for providing low adherence of the powders during milling.

Formation of Ni₃Ta, Ni₂Ta and NiTa by High-Energy Ball Milling and Subsequent Heat Treatment

Authors: Hanna Stefanni Nunes Benites, Bruna Pereira da Silva, Antonio Augusto Araújo Pinto da Silva, Belmira Benedita de Lima, Gilberto Carvalho Coelho, Alfeu Saraiva Ramos

Abstract: The present work reports on the formation of Ni₃Ta, Ni₂Ta and NiTa by high-energy ball milling and subsequent heat treatment. The elemental Ni-25Ta, Ni-33Ta and Ni-50Ta (at.-%) powder mixtures were ball milled under Ar atmosphere using stainless steel balls and vials as well as 300 rpm and a ball-to-powder weight ratio of 10:1. Following, the as-milled samples were uniaxially compacted and heat-treated under Ar atmosphere at 1100°C for 4h. The characterization of as-milled and heat-treated samples was conducted by means of X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry techniques. Supersaturated solid solutions were formed during ball milling of the Ni-25Ta, Ni-33Ta and Ni-50Ta powders. A large amount of Ni₃Ta, Ni₂Ta and NiTa was formed in the mechanically alloyed heat-treated Ni-25Ta, Ni-33Ta and Ni-50Ta alloys, respectively.

423

Structural Evaluation of Ti-Cr-Si-B Powders Produced by High-Energy Ball Milling and Sintering

Authors: Luiz Otávio Vicentin Maruya, Paulo Atsushi Suzuki, Alfeu Saraiva Ramos

Abstract: Multicomponent Ti₆Si₂B-based alloys are potentially attractive for structural applications due to the low Ti₆Si₂B crystallographic anisotropy, and their oxidation resistance are higher than the Ti₅Si₃-based alloys. There is a limited amount of information on effect of alloying on stability of Ti₆Si₂B. The present work reports on the structural evaluation during ball milling and subsequent sintering of Ti-2Cr-22Si-11B and Ti-7Cr-22Si-11B (at-%) powders. The milling process was carried out in a planetary Fritsch P-5 ball mill under Ar atmosphere using hardened steel balls (19 mm diameter), stainless steel vials (225 mL), rotary speed of 300 rpm, and a ball-to-powder weight ratio of 10:1. Samples were collected after different milling times: 20, 60, 180, 300, 420 and 600 min. Addicional wet milling (isopropyl alcohol) for 20 more minutes was adopted to increase the yield powder into the vials. Following, the powders milled for 620 min were uniaxially compacted (20 MPa) in order to obtain cilinder green bodies with 10 mm diameter and subsequently sintered under vacuum at 1100°C for 240 min. The milled powders were characterized by X-ray diffraction, and scanning electron microscopy. The chromium addition have contributed to form a large amount of Ti₆Si₂B in the mechanically alloyed and sintered Ti-2Cr-22Si-11B and Ti-7Cr-22Si-11B alloys.

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