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Some properties of glass-polymer cement
one UP dough moulding compound with synthetic organic reinforcement, were processed under pressures from 20-200 Kg/cm z in the DIN test mould. All could be processed in simple moulds even at low pressures, but there was pronounced variation in mechanical properties and increased water absorption and flaws. Optimum properties were obtained between 50 and 150 Kg/cm 2. Glass fibre damage between 100 and 150 Kg/cm 2 was suggested by a slight decrease in strength. Density tends to increase and water absorption to decrease with pressing pressure, pores due to trapped air being far more frequent in dmc as compared to smc mouldings.
Losses in laminar composite Nb3 Sn at 60 Hz Snowden, D. P., Meyer, C. H. and Sterling, S.A. J App Physics, Vo145, No 6 (June 1974)p 2693 The AC loss in cylindrical samples of Nb3Sn at 60 Hz was studied. Formation of the conductor in cylindrical layers separated by another material increases the critical current density and decreases the loss at high currents. The magnitude of the loss in this material at 10-12 K is comparable to that reported in niobium at 4.2 K. The mechanical strength of glass
textolites based on phosphate bondings Kiselev, B. A. et al Glass and Ceramics (Nov 1974) p 195 (Russian Orig: Steklo i Keramika Vo131 No 3 (March 19 74)) Results of work on phosphate bonded glass fibre fabrics for thermal insulation applications are given. Quartz and alumina fillers were introduced to reduce the acidity of the bonding agent, but strengths were consistently lower than silicon-organic resin bonded materials. It is suggested that a need exists for new thermal corrosion resistant materials and strong reinforcing fillers which can be used with phosphate bonding, or alternatively new inorganic bonding systems less corrosive to the glass fibres, for applications at temperatures continuously above 400°C. Practical problems associated with the application of the finite element method to composite material mieromechanical analyses Adams, D. F. Fibre Science and Technology, Vol 7, No 2 (Apr 1974) plll A number of difficulties associated with the analysis of the micromechanCOMPOSITES. MAY 1975
ical method are discussed. Sources of error in the basic technique as applied to composites are discussed and several suggestions are made as to how they may be overcome. Subsequent sections are concerned with the specific problems of analysis of a material with internal interfaces and random, nongeometrical fibre arrays.
Some properties of glass-polymer cement Golosova, L. V. and lvanova, G. M. Glass and Ceramics (March 1974) p 535 (Russian Original: Steklo i Keramika Vo130 No 8 (Aug 1973)) The feasibility of producing a building panel consisting of an insulating material sandwiched between glass fibrepolymer-cement sheets was studied. The glass was not of the alkali resistant type and efforts were made to use epoxy resin furyl alcohol mixtures to produce a protective coating. Strain measurement techniques for fibre modulus determination Moore, R. L. and Lepper, J. K. Journal of Materials Testing and Evaluation, Vol 2, No 3 (May 19 74) pp 173-175 Two techniques were employed to measure the tensile strain of a high modulus organic fibre in an epoxy matrix. One, a direct averaging strain method, uses two linearly variable differential transformer whose hollow cores are supported by glass beads bonded to the fibre strand specimens. The other method is an indirect method using specimens of several gauge lengths. Crosshead displacement for selected loads was determined for each gauge length, the data fitted to a straight line by least squares fit and the unit strain calculated for each load. The tensile modulus of the fibre strands was found to be 20 x 106 lbf/in 2 and the variation of averages between methods was less than five percent.
METAL MA TRICES
Creep behaviour of an aligned Ag3Mg/ Ag Mg eutectic Kim, Y. G. and Stoloff, N. S. Metallurgical Transactions, Vol 5, No 4 (April 1974)pp 809-815 The eutectic alloy Ag/32.2 atomic % Mg was directionally solidified at rates of between 0.9 and 63.9 cm/h to produce lamellar eutectics with a range of interlamellar spacing. The composites
consisted of lamellae of the phase AgMg and the solid solution Ag/27 atomic % Mg. By suitable heat-treatment the latter could be produced in an ordered form. Between 210 and 270°C the creep rate was reduced and the rupture life increased by ordering in the solid solution and by reduction in the interlamellar spacing. The plastic deformation and fracture of the composites were studied by optical microscopy and fractography and the creep behaviour is discussed in terms of a proposed creep mechanism.
Direct observations of lamellar fault migration in the Pb/Sn eutectic Lin, L. Y. and Courtney, T. H. Metallurgical Transactions, Vol 5, No 2 (Feb 1974) pp 513-514 Direct observations were made of the migration at 150°C of lamellar terminations on cross-sections of a Pb/Sn eutectic alloy. The observed rates of migration agreed very well with those predicted theoretically. Effect of interfacial reaction zone on tensile strength of tungsten fibre-reinforced copper alloy composites Umakoshi, Y., Nakai, K. and Yamane, T. Metallurgical Transactions, Vol 5, No 5 (May 1974)pp 1250-1251 Composites were prepared of tungsten wires (10-20 vol%) in Cu/Mn and Cu/Ni alloy matrices by hot pressing at 800°C. By annealing at 850°C, interaction zones of W/Mn and W/Ni phases respectively were formed at the wire/matrix interface. The zone thickness increased with annealing time. The tensile strengths of the composites were measured as a function of the interaction zone thickness. The apparent strength of the wires went through a maximum at a zone thickness of about 5 gm for the Ni-containing composites and about 10 #m for the Mn-containing composites. The initial improvement in strength with increasing reaction zone thickness is attributed to an improved matrix/wire bonding. Low cycle fatigue behaviour of Ni-Cr lamellar eutectic composites at elevated temperatures Doner, M., Di Primio, J. C. and Salkovitz, E. I. Metallurgical Transactions, Vo15, No 2 (Feb 1974)pp 433439 The low-cycle fatigue properties of Ni/Cr lamellar eutectic composites were studied in the range 300°C-760°C and compared with those of the as-cast alloy. During the initial stages of fatigue both materials exhibited work
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Losses in laminar composite Nb3 Sn at 60 Hz Snowden, D. P., Meyer, C. H. and Sterling, S.A. J App Physics, Vo145, No 6 (June 1974)p 2693 The AC loss in cylindrical samples of Nb3Sn at 60 Hz was studied. Formation of the conductor in cylindrical layers separated by another material increases the critical current density and decreases the loss at high currents. The magnitude of the loss in this material at 10-12 K is comparable to that reported in niobium at 4.2 K. The mechanical strength of glass
textolites based on phosphate bondings Kiselev, B. A. et al Glass and Ceramics (Nov 1974) p 195 (Russian Orig: Steklo i Keramika Vo131 No 3 (March 19 74)) Results of work on phosphate bonded glass fibre fabrics for thermal insulation applications are given. Quartz and alumina fillers were introduced to reduce the acidity of the bonding agent, but strengths were consistently lower than silicon-organic resin bonded materials. It is suggested that a need exists for new thermal corrosion resistant materials and strong reinforcing fillers which can be used with phosphate bonding, or alternatively new inorganic bonding systems less corrosive to the glass fibres, for applications at temperatures continuously above 400°C. Practical problems associated with the application of the finite element method to composite material mieromechanical analyses Adams, D. F. Fibre Science and Technology, Vol 7, No 2 (Apr 1974) plll A number of difficulties associated with the analysis of the micromechanCOMPOSITES. MAY 1975
ical method are discussed. Sources of error in the basic technique as applied to composites are discussed and several suggestions are made as to how they may be overcome. Subsequent sections are concerned with the specific problems of analysis of a material with internal interfaces and random, nongeometrical fibre arrays.
Some properties of glass-polymer cement Golosova, L. V. and lvanova, G. M. Glass and Ceramics (March 1974) p 535 (Russian Original: Steklo i Keramika Vo130 No 8 (Aug 1973)) The feasibility of producing a building panel consisting of an insulating material sandwiched between glass fibrepolymer-cement sheets was studied. The glass was not of the alkali resistant type and efforts were made to use epoxy resin furyl alcohol mixtures to produce a protective coating. Strain measurement techniques for fibre modulus determination Moore, R. L. and Lepper, J. K. Journal of Materials Testing and Evaluation, Vol 2, No 3 (May 19 74) pp 173-175 Two techniques were employed to measure the tensile strain of a high modulus organic fibre in an epoxy matrix. One, a direct averaging strain method, uses two linearly variable differential transformer whose hollow cores are supported by glass beads bonded to the fibre strand specimens. The other method is an indirect method using specimens of several gauge lengths. Crosshead displacement for selected loads was determined for each gauge length, the data fitted to a straight line by least squares fit and the unit strain calculated for each load. The tensile modulus of the fibre strands was found to be 20 x 106 lbf/in 2 and the variation of averages between methods was less than five percent.
METAL MA TRICES
Creep behaviour of an aligned Ag3Mg/ Ag Mg eutectic Kim, Y. G. and Stoloff, N. S. Metallurgical Transactions, Vol 5, No 4 (April 1974)pp 809-815 The eutectic alloy Ag/32.2 atomic % Mg was directionally solidified at rates of between 0.9 and 63.9 cm/h to produce lamellar eutectics with a range of interlamellar spacing. The composites
consisted of lamellae of the phase AgMg and the solid solution Ag/27 atomic % Mg. By suitable heat-treatment the latter could be produced in an ordered form. Between 210 and 270°C the creep rate was reduced and the rupture life increased by ordering in the solid solution and by reduction in the interlamellar spacing. The plastic deformation and fracture of the composites were studied by optical microscopy and fractography and the creep behaviour is discussed in terms of a proposed creep mechanism.
Direct observations of lamellar fault migration in the Pb/Sn eutectic Lin, L. Y. and Courtney, T. H. Metallurgical Transactions, Vol 5, No 2 (Feb 1974) pp 513-514 Direct observations were made of the migration at 150°C of lamellar terminations on cross-sections of a Pb/Sn eutectic alloy. The observed rates of migration agreed very well with those predicted theoretically. Effect of interfacial reaction zone on tensile strength of tungsten fibre-reinforced copper alloy composites Umakoshi, Y., Nakai, K. and Yamane, T. Metallurgical Transactions, Vol 5, No 5 (May 1974)pp 1250-1251 Composites were prepared of tungsten wires (10-20 vol%) in Cu/Mn and Cu/Ni alloy matrices by hot pressing at 800°C. By annealing at 850°C, interaction zones of W/Mn and W/Ni phases respectively were formed at the wire/matrix interface. The zone thickness increased with annealing time. The tensile strengths of the composites were measured as a function of the interaction zone thickness. The apparent strength of the wires went through a maximum at a zone thickness of about 5 gm for the Ni-containing composites and about 10 #m for the Mn-containing composites. The initial improvement in strength with increasing reaction zone thickness is attributed to an improved matrix/wire bonding. Low cycle fatigue behaviour of Ni-Cr lamellar eutectic composites at elevated temperatures Doner, M., Di Primio, J. C. and Salkovitz, E. I. Metallurgical Transactions, Vo15, No 2 (Feb 1974)pp 433439 The low-cycle fatigue properties of Ni/Cr lamellar eutectic composites were studied in the range 300°C-760°C and compared with those of the as-cast alloy. During the initial stages of fatigue both materials exhibited work
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