Development of Ceramic Tool Material and Advanced Multifunctional Coatings for Improved Titanium Machining Process

This proposal seeks to develop improved titanium machining process. Titanium alloys widely used in aerospace industry, are one of the most difficult workpieces to machine, which has become a major limitation in manufacturing. Unlike steel and aluminumbased alloys, titanium cannot take advantage of the high cutting speeds afforded by the use of current state-of-the-art ceramic cutting tools due to its high reactivity with available ceramic tools at the high temperature generated during machining.Moreover conventional coatings which are successful for high speed machining of steel and aluminum do not provide any improvement in titanium machining.For improved titanium machining we propose to develop a new class of ceramic composite cutting tools based on yttrium aluminum garnet (YAG) and advanced multifunctional coatings utilizing state-of-the-art large area filtered arc (LAFAD) technology.Attention will be focussed to make the proposed composite and coatings highly chemically compatible with titanium. Also during processing of composite and coatings, efforts will be directed to lower the temperature rise during titanium machining. SuchYAG based cutting tools and advanced coatings could provide increased machining rates of titanium and increased tool life.Successful completion of the program will provide demonstrated knowledge about the YAG based ceramic cutting tools and advancedcoatings for the improved titanium machining process. The acquired knowledge would have broad commercial applicability due to the large number of commercial airframes and engines that are fabricated from titanium.