SBIR Phase I: Net Shape Fabrication Technology for Fiber Reinforced Composites Densified by Pressureless Sintering

*96-61562 Patterson这个第一阶段的小型企业创新研究项目将展示通过在Si3N4增强纤维中原位对准、晶种和生长针状bDG1-Si3N4颗粒来制造致密、强韧的陶瓷层压基复合材料(CLMC)。这些绿态纤维将被结合到通过流延和堆叠过程制备的a-Si3N4绿态层压基质中。这种加工技术的主要优势是能够将CLMC材料无压烧结到全密度，从而显著降低成本并能够制造出净形状的部件。由于增韧纤维在加入到基体层压板中时还不致密，因此通过无压烧结可以完全致密化复合材料结构，因为纤维和基质相将同时进行致密化。这种独特的材料系统虽然是无压烧结的，但将显示出通过压力辅助致密化烧结的纤维增强复合材料的许多特征--即通过裂纹桥接和纤维拔出获得的高密度、强度和韧性。第一阶段的研究将展示(-Si3N4纤维增韧层板)，从而建立一种制造网状部件的方法(通过无压烧结)，通过纤维拔出等机制显示出高密度和高韧性。纤维增强层合板将用于制造涡轮发动机应用的部件，如燃烧室、排气喷嘴、护罩、襟翼和密封件。预计(-Si3N4)纤维增韧复合材料的成功开发将为陶瓷复合材料的制备提供显著的成本节约。*页：1个DGG1

*** 96-61562 Patterson This Phase I Small Business Innovation Research project will demonstrate the fabrication of dense, strong and tough ceramic laminated matrix composites (CLMCs) through the in-situ alignment, seeding and growth of acicular b DGG1 -Si3N4 particles in Si3N4 reinforcing fibers. These green-state fibers will be incorporated into a a-Si3N4 green-state laminate matrix fabricated by a tape casting and stacking procedure. The key advantage of this processing technology is the ability to do pressureless sintering of the CLMC material to full density thereby significantly reducing the cost and enabling net-shape components to be fabricated. Since the toughening fibers are not yet dense when incorporated into the matrix laminates, the composite structure can be fully densified via pressureless sintering because the fiber and matrix phases will undergo simultaneous densification. This unique materials system, although pressureless sintered, will exhibit many of the characteristics of fiber-reinforced composites sintered via pressure-assisted densification - namely, high density, strength, and toughness achieved through crack bridging and fiber pullout. The Phase I research will demonstrate (-Si3N4 fiber-toughened laminates, thereby establishing a method of fabricating net-shape components (via pressureless sintering) which will exhibit high density and high toughness through mechanisms such as fiber pullout. Fiber-reinforced laminates will be used to fabricate components for turbine engine applications such as combustors, exhaust nozzles, shrouds, flaps and seals. It is anticipated that the successful development of the (-Si3N4 fiber-toughened composite material will provide significant cost savings for the fabrication of ceramic composites. *** Page: 1 DGG1