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Friction and wear behaviour of 2-D and 3-D fibre reinforced metal-matrix composites
I
tesu
Prepared by M.E. Adams, R.S. Bailey, L. Boniface and J.W. Rock
CARBON FIBRES Properties and potential applications of brominated P-100 carbon fibres Jaworske, D.A., Gaier, J.R., Hung, C.C. and Banks, B.A. SAMPE Quarterly Vo118No 1 (October 1986)pp 9-14 After describing the method of preparation of bromide-intercalated pitch-based carbon fibres, the properties of epoxy matrices reinforced with these fibres are discussed. Mechanical properties are similar to those of conventional P-100/epoxy composites, but the resistivity is considerably lowered. Potential applications such as their use in EMI shielding are discussed. X-ray photoelectron spectroscopic studies of carbon fibre surfaces. Part 6: Pilot plant surface treatment and epoxy resin composites Harvey, J., Kozlowski, C. and Sherwood, P.M.A. Journal of Materials Science Fo122 (1987)pp 15851596 Various electrochemical surface treatments were applied to carbon fibres under both galvanostatic and potentiostatic control of cell conditions. The fibre surfaces were analysed using X-ray photoelectron spectroscopy, and the fibres were then impregnatedwith epoxy resin to form unidirectional composites. The interlaminar shear strength (ILSS) was measured using a short beam shear test. Values of 80-90 MPa were achieved. The effect of potential, reaction time, electrolytes and subsequent heatingof fibres in a vacuum on the ILSS are resported. It is concluded that the increase in ILSS was not dependent on the O-Is to C-Is ratio or the degree of carboxyl functionality on the surface. The importance of mechanical keying of the resin to the fibre surface is emphasized.
CERAMIC FIBRES Growth of alumina whiskers by vapour-phase reactions Hayashi, T., Mihoya, M., Yamai, I., Saito, H. and Hirano, S.-I. Journal qf Materials Science Vol 22 (1987)pp 1305-1309 The growth of alumina whiskers by the hydrolysis of aluminium flouride vapour on a polycrystalline alumina surface has been investigated. The morphology of the various whiskers produced under different growth conditions have been examined using microscopy; electron probe micro-analysis was also performed on some whiskers. It was found th at woollike whiskers with diameters of 1--4 p,m and lengths of several millimetres were formed under conditions of low vapour pressures (3 × 10-3 torr2). Increasing the vapour pressure of both H20 and A1F3 simultaneously caused a morphological change from wool-like to needlelike whiskers which grew to lengths of up to 12 mm and diameters of 10-30 p,m.
COMPOSITES. NOVEMBER 1 9 8 7
GENERAL An assessment of damping measurement in the evaluation of integrity of composite beams Lee, B.T., Sun, C.T. and Liu, D. Journal of Reinforced Plastics and Composites Vol 6 No 2 (April 1987)pp 114-125 The effectiveness of damping measurement, using an impulse technique, as a measure of damage present in a composite beam was investigated. Several types of composite material were used; chopped fibre, laminated and hybrid composites and the effects of notches, matrix cracking, artificial delaminations and inclusions were studied. It was found th at the tech n ique was quite successful in beams containing notches and artificial delamination. In the case notches being present it was possible to detect the severity and location of the notches, and for the case of artificially introduced delamination it was found that there was good correlation between the delamination area and the damping coefficient. Matrix cracking and inclusions do not significantly affect the damping characteristics of the beam.
Composite box benin anniysis: Iheoryandexpefiments Bauchau, O.A., Coffenbury, B.S. and Rehfield, L.W.Journal of Reinforced Plastics and Composites Vol 6 No I (Jan uary 1987)pp 25-35 Two methods of adapting classical beam theory to composite structures - - the Saint Venant warping approach and the Eigenwarping approach - - are presented. These techniques take into account the low shearing stiffness and elastic couplings that are a feature of composite structures. Predictions of the two techniques werecomparedwith resultsobtained experimentally. Both methods were found to accurately predictthe overall twist and strain distribution of the exprimental beam, and the Eigenwarping approach was found to yield a more accurate description of the shearing strain distribution. Composite leaf springs for tank trailer suspensions Lo, K.H., McCusker, J.J. and Gottenberg, W.G. Journal of Reinforced Plastics and Composites Vol 6 No 1 (January 1987)pp 100-112 This paper evaluates the applicability of replacing steel leaf springs with composite lea f springs in heavily loaded vehicles. The design of the spring is studied in some detail. Road tests proved the structural integrity of the springs and brought about weight savings of about 113 kg. The composite leaf springs were well received by operators. It is concluded that, to allow the full potential ofth e springs to be achieved, modifications to the existing hardware(ie, mountings, etc) would have to be undertaken. The predictions of R-curves and notched tensile strength for composite laminates Wells, J.K. and Beaumont, P.W.R. Journal of Materials Science Vo122 (1987)pp 1457-1468 In this paper a model is proposed to predict the
crack growth resistance curves (R-curves) and notched tensile strength forcompositelaminates from the properties of the fibre, matrix and interface. The predictions are compared with published experimental data for a variety of laminates and laminate lay-ups.
Viscoelastic/damage modellingoffilament-wound spherical pressure vessels Hackett, R.M. and Dozier, J.D. Journal of Reinforced Plastics and Composites Vol 6 No 2 (April 1987)pp 126-137 The phenomenon of static fatigue or stress rupture in filament-wound spherical pressure vessels is explained by a model in which the viscoelastic properties of the matrix allow a critical level of accumulated internal damage to develop, resulting in the formation of a critical flaw. An analytical model is developed in detail and used in a numerical example to compare with experimental results. It is concluded that the model may form the basis of a means of studying the mechanisms underlying the phenomenon of stress rupture.
METAL MATRICES Friction and wear behaviour of 2-13 and 3-D fibre reinforced metal-matrix composites Majidi, A.P., Pipes, R.B. and Reese, E.D.Journal of Reinforced Plastics and Composites Vol 6 No 2 (April 1987) pp 178-192 The effects of fibre volume fractio n, fibre orientation, contact area and abrasive particle size on the rate and mechanism of wear and the coefficient of friction of alumina fibre/Al-Li composites are investigated. The alumina fibres were in a three-dimensionally braided form. Amongst the findings were: at high wear rates, the braided fibres gave higher wear resistance than unidirectionally reinforced composites; reinforcement decreased the coefficient of friction and wear rate; and that wear rate was highly dependent on specimen orientation, abrasive particle size and contact pressure.
Joining of alumina short-fibre reinforced AA6061 alloy to AA6061 alloy and to itself Suganuma, K., Okatmoto,T. and Suzuki, N.Jourhal of Materials Science Vo122 (1987)pp 1580-1584 Alumina short fibre-fibre reinforced AA6061 aluminium alloy (FRM) was brazed to AA6061 and to itself. The brazing materials were an AA4045 sheet and a BA03 clad sheet with AA3003 alloy at the centre and AA4045 on the outer surfaces. The BA03 sheet was found to be superior for high strength joining. The AA4045 sheet disordered the fibre arrangement near the interface and eroded the AA6061 matrix. The FRM/BA03 interface was stronger than the BA03/AA6061 interface. The strength of the FRM/BA03/ AA6061 join was about 200 MPa while that of the FRM/AA4045/AA6061 join was about 100 MPa.
415
tesu
Prepared by M.E. Adams, R.S. Bailey, L. Boniface and J.W. Rock
CARBON FIBRES Properties and potential applications of brominated P-100 carbon fibres Jaworske, D.A., Gaier, J.R., Hung, C.C. and Banks, B.A. SAMPE Quarterly Vo118No 1 (October 1986)pp 9-14 After describing the method of preparation of bromide-intercalated pitch-based carbon fibres, the properties of epoxy matrices reinforced with these fibres are discussed. Mechanical properties are similar to those of conventional P-100/epoxy composites, but the resistivity is considerably lowered. Potential applications such as their use in EMI shielding are discussed. X-ray photoelectron spectroscopic studies of carbon fibre surfaces. Part 6: Pilot plant surface treatment and epoxy resin composites Harvey, J., Kozlowski, C. and Sherwood, P.M.A. Journal of Materials Science Fo122 (1987)pp 15851596 Various electrochemical surface treatments were applied to carbon fibres under both galvanostatic and potentiostatic control of cell conditions. The fibre surfaces were analysed using X-ray photoelectron spectroscopy, and the fibres were then impregnatedwith epoxy resin to form unidirectional composites. The interlaminar shear strength (ILSS) was measured using a short beam shear test. Values of 80-90 MPa were achieved. The effect of potential, reaction time, electrolytes and subsequent heatingof fibres in a vacuum on the ILSS are resported. It is concluded that the increase in ILSS was not dependent on the O-Is to C-Is ratio or the degree of carboxyl functionality on the surface. The importance of mechanical keying of the resin to the fibre surface is emphasized.
CERAMIC FIBRES Growth of alumina whiskers by vapour-phase reactions Hayashi, T., Mihoya, M., Yamai, I., Saito, H. and Hirano, S.-I. Journal qf Materials Science Vol 22 (1987)pp 1305-1309 The growth of alumina whiskers by the hydrolysis of aluminium flouride vapour on a polycrystalline alumina surface has been investigated. The morphology of the various whiskers produced under different growth conditions have been examined using microscopy; electron probe micro-analysis was also performed on some whiskers. It was found th at woollike whiskers with diameters of 1--4 p,m and lengths of several millimetres were formed under conditions of low vapour pressures (3 × 10-3 torr2). Increasing the vapour pressure of both H20 and A1F3 simultaneously caused a morphological change from wool-like to needlelike whiskers which grew to lengths of up to 12 mm and diameters of 10-30 p,m.
COMPOSITES. NOVEMBER 1 9 8 7
GENERAL An assessment of damping measurement in the evaluation of integrity of composite beams Lee, B.T., Sun, C.T. and Liu, D. Journal of Reinforced Plastics and Composites Vol 6 No 2 (April 1987)pp 114-125 The effectiveness of damping measurement, using an impulse technique, as a measure of damage present in a composite beam was investigated. Several types of composite material were used; chopped fibre, laminated and hybrid composites and the effects of notches, matrix cracking, artificial delaminations and inclusions were studied. It was found th at the tech n ique was quite successful in beams containing notches and artificial delamination. In the case notches being present it was possible to detect the severity and location of the notches, and for the case of artificially introduced delamination it was found that there was good correlation between the delamination area and the damping coefficient. Matrix cracking and inclusions do not significantly affect the damping characteristics of the beam.
Composite box benin anniysis: Iheoryandexpefiments Bauchau, O.A., Coffenbury, B.S. and Rehfield, L.W.Journal of Reinforced Plastics and Composites Vol 6 No I (Jan uary 1987)pp 25-35 Two methods of adapting classical beam theory to composite structures - - the Saint Venant warping approach and the Eigenwarping approach - - are presented. These techniques take into account the low shearing stiffness and elastic couplings that are a feature of composite structures. Predictions of the two techniques werecomparedwith resultsobtained experimentally. Both methods were found to accurately predictthe overall twist and strain distribution of the exprimental beam, and the Eigenwarping approach was found to yield a more accurate description of the shearing strain distribution. Composite leaf springs for tank trailer suspensions Lo, K.H., McCusker, J.J. and Gottenberg, W.G. Journal of Reinforced Plastics and Composites Vol 6 No 1 (January 1987)pp 100-112 This paper evaluates the applicability of replacing steel leaf springs with composite lea f springs in heavily loaded vehicles. The design of the spring is studied in some detail. Road tests proved the structural integrity of the springs and brought about weight savings of about 113 kg. The composite leaf springs were well received by operators. It is concluded that, to allow the full potential ofth e springs to be achieved, modifications to the existing hardware(ie, mountings, etc) would have to be undertaken. The predictions of R-curves and notched tensile strength for composite laminates Wells, J.K. and Beaumont, P.W.R. Journal of Materials Science Vo122 (1987)pp 1457-1468 In this paper a model is proposed to predict the
crack growth resistance curves (R-curves) and notched tensile strength forcompositelaminates from the properties of the fibre, matrix and interface. The predictions are compared with published experimental data for a variety of laminates and laminate lay-ups.
Viscoelastic/damage modellingoffilament-wound spherical pressure vessels Hackett, R.M. and Dozier, J.D. Journal of Reinforced Plastics and Composites Vol 6 No 2 (April 1987)pp 126-137 The phenomenon of static fatigue or stress rupture in filament-wound spherical pressure vessels is explained by a model in which the viscoelastic properties of the matrix allow a critical level of accumulated internal damage to develop, resulting in the formation of a critical flaw. An analytical model is developed in detail and used in a numerical example to compare with experimental results. It is concluded that the model may form the basis of a means of studying the mechanisms underlying the phenomenon of stress rupture.
METAL MATRICES Friction and wear behaviour of 2-13 and 3-D fibre reinforced metal-matrix composites Majidi, A.P., Pipes, R.B. and Reese, E.D.Journal of Reinforced Plastics and Composites Vol 6 No 2 (April 1987) pp 178-192 The effects of fibre volume fractio n, fibre orientation, contact area and abrasive particle size on the rate and mechanism of wear and the coefficient of friction of alumina fibre/Al-Li composites are investigated. The alumina fibres were in a three-dimensionally braided form. Amongst the findings were: at high wear rates, the braided fibres gave higher wear resistance than unidirectionally reinforced composites; reinforcement decreased the coefficient of friction and wear rate; and that wear rate was highly dependent on specimen orientation, abrasive particle size and contact pressure.
Joining of alumina short-fibre reinforced AA6061 alloy to AA6061 alloy and to itself Suganuma, K., Okatmoto,T. and Suzuki, N.Jourhal of Materials Science Vo122 (1987)pp 1580-1584 Alumina short fibre-fibre reinforced AA6061 aluminium alloy (FRM) was brazed to AA6061 and to itself. The brazing materials were an AA4045 sheet and a BA03 clad sheet with AA3003 alloy at the centre and AA4045 on the outer surfaces. The BA03 sheet was found to be superior for high strength joining. The AA4045 sheet disordered the fibre arrangement near the interface and eroded the AA6061 matrix. The FRM/BA03 interface was stronger than the BA03/AA6061 interface. The strength of the FRM/BA03/ AA6061 join was about 200 MPa while that of the FRM/AA4045/AA6061 join was about 100 MPa.
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