./. Appl. Ceram. Technol, 612/151-163(2009) DO:10.J11.1747402.2008.02331.x Applied Ceramic Technolog ceramic Product Development and Commercialization Design Guidelines for In-Plane Mechanical Properties of SiC Fiber-Reinforced Melt-Infiltrated SiC Composites Ohio Aerospace Institute, Cleveland, Ohio 44142 Vijay V.Pt Materials and Simulation Technical Center, Goodrich Corporation, Brecksville, Ohio 44141 In-plane tensile stress-strain, tensile creep, and after-creep retained tensile properties of melt- infiltrated SiC-SiC com- posites reinforced with different fiber types were evaluated with an emphasis on obtaining simple or first-order microstructural design guidelines for these in-plane mechanical properties. Using the minimatrix approach to model stress-strain behavior and he results of this study, three basic general design criteria for stress and strain limits are formulated, namely a design stress limit, a design total strain limit, and an after-creep design retained strength limit. It is shown that these criteria can be useful for Introduction for composite designers and fabricators who often have to weigh the benefits of cost savings, for example, a less Woven silicon carbide fiber-reinforced melt- infil- expensive fiber, with performance targets demanded by rated(MD)silicon carbide matrix composites are an application. Constituent-based and fiber-architec- considered to be important enabling materials for ture-based design models need to be developed to as- composites(CMC); however, even within that subset, given application. To validate these models, composite onsiderable variations in thermomechanical properties property data are needed over wide variations in con- are possible depending on the composite constituent stituent compositions, geometries, and content. A con- materials, geometries, and content. This is important siderable amount of data has been generated on composites with a wide variation in fber fraction and fiber architectures for the Sylramic-iBn (Syl-iBN)fiber- ork was financially supported by both internal Goodrich and NASA Supers reinforced MI composite system. 4 ./- These results .grams as well as a partially reimbursable Space Act Agreement between Goodrich and have enabled the development of simple constituent based and fiber-architecture- based relationships that can an Ceramic guide designers, fabricators, and end users in predictingDesign Guidelines for In-Plane Mechanical Properties of SiC Fiber-Reinforced Melt-Infiltrated SiC Composites Gregory N. Morscher* Ohio Aerospace Institute, Cleveland, Ohio 44142 Vijay V. Pujar Materials and Simulation Technical Center, Goodrich Corporation, Brecksville, Ohio 44141 In-plane tensile stress–strain, tensile creep, and after-creep retained tensile properties of melt-infiltrated SiC–SiC com￾posites reinforced with different fiber types were evaluated with an emphasis on obtaining simple or first-order microstructural design guidelines for these in-plane mechanical properties. Using the minimatrix approach to model stress–strain behavior and the results of this study, three basic general design criteria for stress and strain limits are formulated, namely a design stress limit, a design total strain limit, and an after-creep design retained strength limit. It is shown that these criteria can be useful for designing components for high-temperature applications. Introduction Woven silicon carbide fiber-reinforced melt-infil￾trated (MI) silicon carbide matrix composites are considered to be important enabling materials for high-temperature turbine1,2 applications. MI matrix SiC composites are a subset of SiC/SiC ceramic matrix composites (CMC); however, even within that subset, considerable variations in thermomechanical properties are possible depending on the composite constituent materials, geometries, and content.3–6 This is important for composite designers and fabricators who often have to weigh the benefits of cost savings, for example, a less expensive fiber, with performance targets demanded by an application. Constituent-based and fiber-architec￾ture-based design models need to be developed to as￾sess whether a given fiber type can meet the property requirements or the cost/performance objectives for a given application. To validate these models, composite property data are needed over wide variations in con￾stituent compositions, geometries, and content. A con￾siderable amount of data has been generated on composites with a wide variation in fiber fraction and fiber architectures for the Sylramic-iBN (Syl-iBN) fiber￾reinforced MI composite system.4,7–11 These results have enabled the development of simple constituent￾based and fiber-architecture-based relationships that can guide designers, fabricators, and end users in predicting Int. J. Appl. Ceram. Technol., 6 [2] 151–163 (2009) DOI:10.1111/j.1744-7402.2008.02331.x Ceramic Product Development and Commercialization This work was financially supported by both internal Goodrich and NASA Supersonic programs as well as a partially reimbursable Space Act Agreement between Goodrich and NASA. *gregory.n.morscher@nasa.gov r 2008 The American Ceramic Society