SBIR Phase II: Rapid Superplastic Forming of Titanium Matrix Composites

这个小企业创新研究（SBIR）二期项目将结合颗粒增强钛金属基复合材料（PRMMC）和创新成型工艺来生产飞机发动机导管。金属基复合材料是为高温下的刚度而设计的，很难形成有用的形状。一种独特的现象——内应力超塑性，通过在同素异向相变温度范围内重复热循环，在钛PRMMC中仅施加轻应力就能产生均匀的粘性流动，从而解决了成形问题。一期产生了近300%的单轴拉伸。第二阶段的工艺开发将把PRMMC复合材料转化为有用的轴对称管状，例如用于商用飞机发动机的导管，通过利用先进的红外加热（每分钟1-4次的快速热循环）在30分钟的超塑性成形中“吹塑”预成型管的最终几何形状。该项目将扩大单轴结果到多轴板胀形和管胀形工艺在4英寸乘12英寸的规模。最后的组件将复制航空发动机工业的管道组件。商业应用包括飞机发动机导管、热交换器管、海上管件和阀门等部件。复杂形状的部件，特别是那些需要高强度和耐腐蚀性的轴对称部件，将受益于这项技术。预计这些应用将跨越许多市场领域，包括航空航天、工业和消费市场。

This Small Business Innovation Research (SBIR) Phase II project will combine particulate reinforced titanium metal matrix composites (PRMMC) with an innovative forming process to produce aircraft engine ducting. Metal matrix composites, designed for stiffness at elevated temperatures are extremely difficult to form into useful shapes. A unique phenomenon, internal stress superplasticity, circumvents the forming problem by producing uniform viscous flow in titanium PRMMC's with only a light applied stress during repeated thermal cycling through the allotropic phase transformation temperature range. Phase I produced uniaxial stretching of nearly 300%. Phase II process development will transform PRMMC composite into useful axisymmetric tubular shapes, such as used for ducting on commercial aircraft engines, by utilizing advanced infrared heating (rapid thermal cycling at 1-4 cycles per minute) to "blow mold" a preform tube into final geometry in 30 minutes of superplastic forming. The project will scale up uniaxial results to multiaxial sheet bulging and tube bulging processes on a 4 inch by 12 inch scale. The final component will replicate a duct component from the aerospace engine industry. Commercial applications include components such as aircraft engine ducting, heat exchanger tubing, offshore pipe fittings, and valves. Complex shaped components, particularly those axisymmetric in nature which require high strength and corrosion resistance, will benefit from this technology. It is anticipated that these applications will span many market areas including aerospace, industrial, and consumer markets.