Particle fracture and phase transformations induced by electrical discharge assisted mechanical milling

• Autorzy: Calka A. , Wexler D.

Warianty tytułu

PL

Rozdrabnianie cząstek i przemiany fazowe wzbudzane przez mielenie udarowe w obecności plazmy wyładowania elektrycznego

• Konferencja: Advanced Materials and Technologies, AMT'2004 : XVII Physical Metallurgy and Materials Science Conference (XVII; 20-24.06.2004; Łódź, Polska)
• Języki publikacji: EN

Abstrakty

EN

A novel device for milling, incorporating high voltage, low current electrical discharges was constructed and its application for materials processing investigated [1, 2]. This type of milling has been found to result in rapid fracture rates, enhanced mechano-chemical reactions and novel reaction paths. We present recent studies of fracturing, agglomeration and phase formation using this method applied to a vibrational rod mill. The effect of spark discharge milling condition on particle size and surface morphology was investigated for a number of different materials including; alumina, NiZr, Ni plus Si, Mg-Zn alloy of eutectic composition. In these experiments, variations in milling vibrational amplitude resulted in variations in nominal average spark length for samples discharged milled under repeated impact. It was confirmed that during discharge milling, rapid fracturing occurs wervery short milling times and is accompanied by the formation of both fine particles and agglomerates. Large vibrational amplitudes tended to promote increased particle agglomeration in both ceramics and metals, while discharge milling with lower vibrational amplitudes promoted the formation of finer particles and smaller agglomerates. In the case of alumina, particle coarsening and spheroidisation was believed to result from repeated sintering of individual particles. For metals, alloys and metallic glasses, the tendency for coarsening and formation of spherical particles resulted from some combination of partial melting and deformation. Spark milling of Mg-Zn eutectic decomposition product was found to result in formation of the metastable eutectic phase, Mg7Zn3.

Słowa kluczowe

EN

mechanical milling; ball milling; electric discharge; plasma; materials fracture; alloying

PL

mielenie mechaniczne; wyładowania elektryczne; plazma; stopowanie

• Wydawca: Wydawnictwo SIGMA-NOT
• Czasopismo: Inżynieria Materiałowa
• Rocznik: 2004
• Tom: R. XXV, nr 3
• Strony: 465--468
• Opis fizyczny: Bibliogr. 7 poz., rys.

Twórcy

autor

Calka A.

• Faculty of Engineering, University of Wollongong,Wollongong, Australia

autor

Wexler D.

• Faculty of Engineering, University of Wollongong,Wollongong, Australia

Bibliografia

• [1] Całka A., Wexler D.: NATURĘ, 419 (Sept 12, 2002), p. 147.
• [2] Całka A., Wexler D.: Mat. Sci. Forum, Vol. 386-388 (2002) 125
• [3] Całka A.,. Varin R.A., Wexler D.: Proc. Int. Symp. on Processing and Fabrication of Advanced Materials-PFAM XI, 2002, Materials Solutions Conference & Exposition, Columbus, OH, October 7-10, (2002) Eds. T.S. Srivatsan and R.A. Varin, ASM International, Materials Park, OH (in press).
• [4] Kimura H., Kabayashi S., J. Japan Inst. Metals, Vol. 58, (l994) p. 201.
• [5] Kimura H., Nanostructured Materials, Vol. 9 (1997) P. 93.
• [6] Mishra R.S., Mukherjee A.K., Materials Science and Engineering A 287 (2000), p. 178.
• [7] Całka A., Radlinski A. P.: Appl. Phys. Lett, 58 (1991), p. 119.