Fracture mechanics, crack propagation and microhardness studies on flux grown ErAlO3 single crystals

Abstract

Abstract: Results on fracture mechanics and crack propagation have been obtained, making use of Vickers microhardness studies on two different crystallographic planes [(110) and (001)] of flux grown erbium aluminate crystals in the load ranging from 10 similar to 100 g. The variation of microhardness with load which is best explained by Hays and Kendall's law leads to the load independent values of hardness. Classification of cracks is dealt with and it is reported that the transition from Palmqvist to median types of cracks occurs at higher loads. The values of fracture toughness (K-C), and brittleness index (B-i) are calculated using median types of cracks.

Key words:

K.K.Bamzai, P.N.Kotru, B.M.Wanklyn. Fracture mechanics, crack propagation and microhardness studies on flux grown ErAlO3 single crystals[J]. J Mater Sci Technol, 2000, 16(04): 405-410.

References

[1] P.J.Burnett, T.F.Page: Instr. Phys. Conf .Ser., 1985,75, 789.
[2] T.Hioki, A.Itoh, M.Okhubo, S.Noda, D.Dot,Kawamot and O.Kamigaito: J. Mat. Sci., 1986, 21,1321.
[3] P.N.Kotru, A.K.Razdan, B.M.Wanklyn: J. Mat. Sci.,1989, 24, 793.
[4] C.Hays, E.G.Kendall: Metallography, 197:3, 6, 275.
[5] B.M.Wanklyn: J. Cryst. Growth, 1969, 5, 323.
[6] S.K.Arora, N.M.Batra: VHN of CaMoO_4 personalcommunication 1984.
[7] S.Beigh, P.N.Kotru, B.M.Wanklyn: Mat. Chem.Phy., 1995, 40,99.
[8] V.P.Bhatt, C.F.Desai:Bull. Mater. Sci., 1982, 4, 23.
[9] C.A.Brookes: 2nd Int. Conf. on Science or Hard Materials (Rhodes) Inst. Phys. Conf Ser., 1986, 75,Ch.3 (Bristol: Hilger)
[10] Y.Deslandes, E.Alva Rosa, F.Brisse, T.Meneghini:J.Mat. Sci., 1991, 26, 2769.
[11] H.Buckle: Metall. Rev., 1950, 4, 13.
[12] J.R.Pandya, L.J.Bhagia, A.J.Shah:Bull. Mater. Sci.,1983, 5, 79.
[13] K.K.Sharma, P.N.Kotru, R.P.Tandon, B.M.Wanklyn:J. Phys. Condens. Matter, 1998, 10, 5277.
[14] K.K.Bamzai, P.N.Kotru, B.M.Wanklyn: Applied Surface Science, 1998, 133,195.
[15] K.K.Sharma, P.N.Kotru, R.P.Tandon, B.M.Wanklyn:Mater. Sci. Eng. B, 1999, 57, 197.
[16] K.Bamzai, P.N.Kotru, B.M.Wanklyn: Cryst. Res.Technol., 1996, 31(6), 813.
[17] K.K.Sharma, P.N.Kotru, B.M.Wanklyn: Cryst. Res.Technol., 1994, 81, 251.
[18] A.Jain, A.K.Razdan, P.N.Kotru, B.M.Wanklyn: J.Mat. Sci., 1994, 29, 3847.
[19] F.Kick: Das gesetz der Proportionalen Widerstandeand Seine Anwendung, Delipzig Felix 1885.
[20] C.B.Ponton, R.D.Rawling: Br. Ceram.Trans. J.,1989, 88, 83.
[21] B.Vengatesan, N.Kanihah, P.Ramaswamy: J. Mat.Sci. Lett., 1986, 5, 987.
[22] B.R.Lawn, D.B.Marshall: J. Am. Ceram. Soc., 1979,62, 347.
[23] H.Ishikaa, N.Shinkai: J. Am. Ceram. Soc., 1980, 65,C-124.
[24] B.R.Lawn, A.G.Evans: J. Mat. Sci., 1977, 12, 2195.
[25] B.R.Lawn, A.G.Evans, D.B.Marshall: J. Am. Ceram.Soc., 1980, 63, 574.
[26] D.G.Bhat: ibid, 1981, 64, C-166.
[27] K.Nihara, R.Morena, D.P.H.Hasselman: J. Mater.Sci. Lett., 1982, 1,13.
[28] N.A.Goryunova, A.S.Borshchevskii, D.N.Tretiakov:"Hardness, Semiconductor and Semimetals", eds.R.K.Willardson and Albert C.Beer, Academic Press,New York-London, 1968, 492.
[29] J.H.Westbrook: "The Science of Hardness Testing andits Research Applications", eds. J.H.Westbrook andH.Conard, Pub. American Society for Metal, MetalPark, Ohio, 492.
[30] J.P.Cahoon, W.H.Broughton, A.R.Katzuk: Metall.Trans., 1971, 2,1979.
[31] R.Wytt: in Metals, Ceramics and Polymers (London,1974), Ch.5, 6.