composites Part A: applied science and manufacturing ELSEVIER Composites: Part A 32 (2001)1021-1029 www.elsevier. com/locate/compositesa Fabrication of fiber-reinforced celsian matrix composites N.p. Bansal.,j.a. . Setlock bDepartment of Materials Science and Engineering Case Western Resenve Universiry, Cleveland, OH 44106,USA Abstract A method has been developed for the fabrication of small diameter, multifilament tow, fiber-reinforced ceramic matrix composites. Its application has been successfully demo emonstrated for the Hi-Nicalon/celsian system. Strong and tough celsian matrix composites, reinforce d cutting and stacking of eg tapes in the desired orientation, and hot pressing The monoclinic celsian phase in the matrix was produced in s -2Si02 mixed precursor synthesized by solid state reaction from metal oxides. Hot pressing resulted e fiber-reinforced composites. The unidirectional composites having ~42 vol. of fibers exhibited graceful tests at room temperature. Values of yield stress and strain were435±35 f900±60 MPa were observed. Young's' modulus of the composites Keywords: A. Cer 1. Introductio sian, and the orthorhombic phase are found only in synthetic products. The hexacelsian phase is thermodynamically Monoclinic celsian BaAlSi2O8 (BAS)and SrAl2S stable at temperatures between 1590C and the melting (SAS) are refractory materials having melting points higher point whereas the celsian phase is stable at temperatures than 1700 xist as a meta- reduction a ance to alkali stable phase at all temperatures from 1590C to room atta goes a rapio he orthorhom- ge volume change of ~3% is always treatment at ansformation into and very h SAS turbine er also being forced com application Asexist phase, common and the multifilament ring phase. The h small diameter Nicalon [11] and HPZ 12] fibers have ve dy was to Corresponding a develop the fabrication of small diameter, multifilament tow E-mail address: nar fiber-reinforced celsian matrix composites. Microstructures -835X( ront matter 1359-835x//s psi359-835xo0)00169-
            
                     ! " #    $ %     &' '  (    " )     *+ "
               !       "      #     $  % #  &   &      ! %'  $      #   &   ! !    # !  &  !      &   &   &           & (         !        &   &   )*+,-).+,-.,/-.,.    # 0 #       $  &     #       (     &
1. 2    &    !                  3   #    ! 1/+
/+ 4  ).*
))52 #    &  6))
7) 4 !  8 &9       !     57+
+ :
.))5 ;   <  &  , )-  =  '   >'4'?@ ' @  4      4    ..,A >?  ..,A >?   #   &  &   &  5*))
' (            !  # &      (      
57))
'  #  !         >    & ?     (# ! !           &  !    &   &  ! !     B5C  &   & &    & &          &   '            &  ' %'    &         #             &      B.C '    &  &         B/-7C  &                 &         #     &     (      #  !       #    &  ( &     !             #  #    (    # #     ! 5+6)
'    &   !         ! 5+6)
' $!             5+6)
'     
/))
'  &         B*C         # &    & 
/2 (      "      #   !#      $!     
5.))
'  &               #  &&   BAC  #    B6C "   !   &   !              B5)C
 #               & B55)C (  &    )*+,-).+,-.,/-.,. >? !    #            #  &     &-     ! &  '3D ' ' 7    B/-7C         B55C  $E B5.C      ( F    # !           !       4   '=   /. >.))5? 5).5-5).6 5/+6 A/+G%)5%H    
.))5 ;   <  &  ""= 5/+6 A/+G>))?))576 G !!!%%  '  &  (= 5 .57 1// /A++@ = 5 .57 1// ++11 &   .  I & >  ?