HiPerComp™ composites

The matrix of HiPerCompTM composite consists primarily of SiC and Si. The coefficient of thermal expansion (CTE) of Si and SiC differ only slightly, such that relatively wide ranges of matrix composition are possible while still providing an adequate match to the CTE of the SiC-based fibers. Typically the HiPerComp composites have residual silicon levels of 5 to 15vol%. 

Thermal and mechanical properties of HiPerComp composites have been measiued at various stages during their development. Consequently the data presented here differs somewhat from previously published data summaries [1] since the material system and processing techniques have continued to evolve with time. The data presented here for Prepreg HiPerComp was mostly measured as part of the DOE-sponsored Continuous Fiber Ceramic Composites (CFCC) program on material fabricated in 2000 and 2001. Data for the Slurry Cast HiPerComp material was measured in 2003. Please note that this data is presented for informative purposes only, and should not be construed as, or used for, engineering specifications. 

FIGURE 5. Thermal properties ofprepreg and slurry cast HiPerComp composites with Hi-Nicalon fibers. 

TABLE 2. Summary of the Elastic Properties of HiPerComp Composites. 

The tensile creep and creep rupture properties of Prepreg HiPerComp composites have also been evaluated in air for times up to 1000 hours. These data are summarized in... 

FIGURE 11. Photographs of inqjact damage in Slurry Cast (tcp) and Prepr (bottom) HiPerComp composites caused by 4mm chrome-steel projectiles fired at various velocities. The photographs show the back sides of the samples, which generally showed mote damage than the impact sides. 

Figure 11 Thermal resistance of C-C/Cu-clad-Mo joint (top) and C-SiC/Cu-clad-Mo joint (bottom). The decrease in Rcir is small (<10%) for clad layer thickness up to 30% and is not visually resolvable in the figure. The lower figure also shows the projections for HiPerComp SiC-SiC composite.

G.S. Corman and K.L. Luthra, Silicon Melt Infiltrated Ceramic Composites (HiPerComp ), in Handbook of Ceramic Composites, N.P. Bansal, Ed., Kluwer Academic Publishers, Bostan, MA, 2004, pp. 99-115. 

Silicon Melt Infiltrated Ceramic Composites (HiPerComp ... 

The in-plane tensile fracture response of HiPerComp materials are typically characterized by a stress-strain curve as shown in Figure 6 when measured in a simple displacement-controlled method. In general, the curve can be divided into four sections (shown by the dotted lines in Figure 6), with the first section representing the simple linear elastic loading of the composite. As the stress increases multiple matrix cracks are generated in the composite and the fibers bridging the cracks are shear debonded from the matrix... 

The HiPerComp family of ceramic matrix composites, based on silicon melt infiltration composite technology invented by GE, offer a unique combination of high temperature thermal and mechanical properties that make them highly suited for gas turbine engine... 

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