October 20 Laminated silicon Nitride stacks (a) DRape T Interlayer Interlayer Ta ape Tape Interlay Interlayer Fig 10. (a-d) Microstructure of sintered tapes-laminated pressureless; (a+ b) composition Cer 20. (c+d)Cer60(scanning electron microscopy, SEM of elongated B-grains or residual stresses in the sintered laminate sintered tapes is pure B-Si3N4, irrespective of the direction in systems, X-ray diffraction patterns of planes parallel to and which the samples have been investigated. This means that there rpendicular to the casting plane have been compared is a homogeneous phase distribution and no hint of an aniso- (Fig. 12). There is no difference in the peak areas and in the tropic microstructure peak heights when irradiating samples from different direction Therefore, it is more likely that there may be small defects like This indicates that there is no orientation within the individual pores or inclusions present between the single sheets caused by tape layers. The peaks also indicate that the phase content in the ufficient processing, which could, in some cases, be detected 270299330365403446493 ◆cer30 Cer 50(perpendicular) 6.46.56.6 5.55.657 In(e /MPa) in(c。MPa Fig. 11. (a)Weibull plot of strength of tapes laminated by compression. (b) Weibull plot of strength measurements of tapes laminated using pastes containing the and 60 vol%of elongated b-grains or residual stresses in the sintered laminate systems, X-ray diffraction patterns of planes parallel to and perpendicular to the casting plane have been compared (Fig. 12). There is no difference in the peak areas and in the peak heights when irradiating samples from different directions. This indicates that there is no orientation within the individual tape layers. The peaks also indicate that the phase content in the sintered tapes is pure b-Si3N4, irrespective of the direction in which the samples have been investigated. This means that there is a homogeneous phase distribution and no hint of an aniso￾tropic microstructure. Therefore, it is more likely that there may be small defects like pores or inclusions present between the single sheets caused by insufficient processing, which could, in some cases, be detected Fig. 10. (a–d) Microstructure of sintered tapes-laminated pressureless; (a1b) composition Cer20, (c1d) Cer60 (scanning electron microscopy, SEM, plasma-etched). Fig. 11. (a) Weibull plot of strength measurements of tapes laminated by compression. (b) Weibull plot of strength measurements of tapes laminated using pastes containing the ceramic precursor in 30, 50, and 60 vol%. October 2005 Laminated Silicon Nitride Stacks 2719