25 µm

1. Diffusion Bonding of TitaniumMatthew N. Cavalli, University of North Dakota Main Campus, DMR 0907616 Titanium (Ti) and its alloys are widely used in aerospace and chemical industries because of their high specific strength, good erosion resistance and favorable high temperature properties. Unfortunately, traditional welding of titanium alloys is problematic if any oxygen is present. In this work, commercially pure Ti has been diffusion bonded using a silver interlayer, a copper interlayer or without any interlayer. The microstructure and properties of the bonded zone are strongly affected by the bonding temperature, bonding time and interlayer type. A joint strength of 98% of the base metal strength (511 MPa) has been achieved using a copper interlayer at 1030C for 10 hours. a b 25 µm Scanning electron microscope image of Ti-Cu-Ti joint centerline bonded at 1100C for 10h showing regions of a) eutectic α-Ti / CuTi3 and b) Ti-Cu solid solution.

2. Diffusion Bonding of TitaniumMatthew N. Cavalli, University of North Dakota Main Campus, DMR 0907616 The primary broader impact activity completed to date was the planning and implementation of ‘Experience Engineering’. This week-long day camp for high school students included activities like metal casting, fabrication of composite materials, computer bridge design, production of ethanol and flight training for unmanned aerial vehicles. Seven students participated. Final reviews from the participants ranged from ‘It [Experience Engineering] was awesome!’ to ‘I love this program!’. Five of the seven participants in the ‘Experience Engineering Summer Camp 2010’ – a weeklong day camp incorporating demonstrations in mechanical, electrical, geological, civil and chemical engineering.