This Small Business Innovation Research (SBIR) Phase I project will develop a new ceramic cutting tool material for machining titanium alloys. Only limited success has been achieved by new coatings to prevent dissolution of carbon from current tungsten carbide tools into titanium. Phase I will develop a new class of ceramic-composite cutting tools based on yttrium-aluminum garnet (YAG), whose mechanical properties are similar to those of alumina and which are more compatible chemically with titanium. The research will make an initial thermodynamic phase compatibility analysis of reinforced YAG composites with titanium, experiment with YAG-based composite processing, characterize reactions occurring at the ceramic-titanium interface, and evaluate key mechanical properties. Titanium alloys, widely used in the aerospace industry, are one of the most difficult workpieces to machine. Their high reactivity limits the use of state-of-the-art ceramic tools. A new YAG-based, ceramic-composite cutting tool could reduce the costs of titanium alloy products by increasing machining rates and reducing production time.