TY - JOUR
T1 - Effect of a diffusion-enhancing hole on the densification of a thick-section 2D C/SiC composite
AU - Zhang, Jiaxin
AU - Liu, Yongsheng
AU - Cheng, Laifei
AU - Zhao, Hui
AU - Wang, Jing
AU - Zhang, Yi
AU - He, Zongbei
AU - Zhang, Baoxi
AU - Zhang, Litong
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/12
Y1 - 2019/12
N2 - Diffusion-enhancing holes (DEHs) have been used to mitigate the large density gradients that are formed in the thick-section ceramic matrix composites (CMCs) fabricated by chemical vapor infiltration (CVI). However, the densification characters of the thick-section CMCs with DEHs through vapor infiltration remain a concern. Here, the densifications of a10-mm-thick two dimensional (2D) C/SiC composite with or without DEHs are investigated by experiments and calculations. Results showed both the measured densities, the predicted final densities, and the density growth rates (DGRs) for the composite with DEHs (diameters of 2 or 4 mm) are higher than those of the counterpart without DEHs, due to the forming of dense rings (DRs) around DEHs and the increased infiltration in the large pores (diameter > 52 μm). In addition, the diffusion increase in infiltration with DEHs is attributed to the increase of Knudsen diffusion resulted from the reopening of the blocked/sealed pores by DEH-machining.
AB - Diffusion-enhancing holes (DEHs) have been used to mitigate the large density gradients that are formed in the thick-section ceramic matrix composites (CMCs) fabricated by chemical vapor infiltration (CVI). However, the densification characters of the thick-section CMCs with DEHs through vapor infiltration remain a concern. Here, the densifications of a10-mm-thick two dimensional (2D) C/SiC composite with or without DEHs are investigated by experiments and calculations. Results showed both the measured densities, the predicted final densities, and the density growth rates (DGRs) for the composite with DEHs (diameters of 2 or 4 mm) are higher than those of the counterpart without DEHs, due to the forming of dense rings (DRs) around DEHs and the increased infiltration in the large pores (diameter > 52 μm). In addition, the diffusion increase in infiltration with DEHs is attributed to the increase of Knudsen diffusion resulted from the reopening of the blocked/sealed pores by DEH-machining.
KW - Ceramic matrix composites
KW - Chemical vapor infiltration
KW - Densification
UR - http://www.scopus.com/inward/record.url?scp=85069879624&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2019.07.043
DO - 10.1016/j.jeurceramsoc.2019.07.043
M3 - 文章
AN - SCOPUS:85069879624
SN - 0955-2219
VL - 39
SP - 4609
EP - 4616
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 15
ER -