Numerical simulation for fabrication of C/SiC composites in isothermal CVI reactor

A two-dimensional mathematical model for fabrication of C/SiC composites in a hot-wall isothermal chemical vapor infiltration reactor was developed. Transport phenomena of momentum, energy and mass in conjunction with infiltration induced changes of preform structure were taken into account. The integrated model was solved by finite element method to numerically simulate flow field, temperature field, concentration field and densification behavior of C/SiC composites at a typical operating condition of isothermal CVI process. Calculated results shows that three different stages exist in densification behavior of C/SiC composites, that is, micro-pores infiltration dominated stage, mixture dominated stage and macro-pores infiltration dominated stage. Favorable agreement is then seen between calculated results and corresponding experimental data which implies that this mathematical model is valid and reasonable to characterize isothermal CVI process of C/SiC composites.

[1]  B. Sheldon,et al.  Reaction and Diffusion Kinetics During the Initial Stages of Isothermal Chemical Vapor Infiltration , 1991 .

[2]  R. Gadow,et al.  Fiber-reinforced silicon carbide , 1986 .

[3]  T. Starr.  Gas transport model for chemical vapor infiltration , 1995 .

[4]  R. Currier.  Overlap model for chemical vapor infiltration of fibrous yarns , 1990 .

[5]  R. Naslain.  Ceramic matrix composites , 1995, Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences.

[6]  B. Sheldon,et al.  Vapor-Phase Fabrication and Properties of Continuous-Filament Ceramic Composites , 1991, Science.

[7]  T. Chou,et al.  Modeling of an improved Chemical Vapor infiltration Process for Ceramic Composites Fabrication , 1990 .

[8]  Y. Makarov,et al.  Modeling of SiC-matrix composite formation by isothermal chemical vapor infiltration , 2004 .

[9]  R. Warren.  Ceramic-Matrix Composites , 1991 .

[10]  R. Naslain.  Design, preparation and properties of non-oxide CMCs for application in engines and nuclear reactors: an overview , 2004 .

[11]  Deepak,et al.  Mathematical Model for Chemical Vapor Infiltration in a Microwave‐Heated Preform , 1993 .

[12]  Pradeep K. Agrawal,et al.  1-D model for forced flow-thermal gradient chemical vapor infiltration process for carbon/carbon composites , 1996 .

[13]  G. Vignoles,et al.  Modeling of isobaric–isothermal chemical vapor infiltration: effects of reactor control parameters on a densification , 2005 .

[14]  E. Wolf,et al.  Simulation of a multiple substrate reactor for chemical vapor infiltration of pyrolytic carbon within carbon‐carbon composites , 1993 .

[15]  I. Tanaka,et al.  Si3N4/SiC‐Whisker Composites without Sintering Aids: III, High‐Temperature Behavior , 1991 .