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Titanium Research SummaryThe U.S. Marines ' and U.S. Army's next-generation, titanium-intensive M777 howitzer offers reduced weight, increased mobility, and improved survivability over its aging, M198 steel-based predecessor. The National Center for Excellence in Metalworking Technology (NCEMT), operated by Concurrent Technologies Corporation, is helping to meet M777 program goals for cost, performance, and production schedule by developing near-net-shape manufacturing routes for traditionally machined and welded components. Under two projects sponsored by the Navy Manufacturing Technology Program, the NCEMT has developed investment cast spade and saddle components as well as flowformed tubes and forged bell housings. This paper summarizes the results of the two ongoing projects.

An understanding of the underlying phenomena when characterizing material performance requires knowledge in several areas, including the chemistry and physics of the early stages of oxidation, chemistry and bonding at the substrate/oxide interface, effect of segregants on the strength of bonding, transport processes through the scales that are formed during corrosion, mechanisms of residual stress generation and relief, and fracture behavior at the oxidekubstrate interface. Specific objectives of the program described here are to (a) systematically investigate the relationships among substrate composition and properties and scalekoating adherence, damage tolerance, and micromechanical properties; (b) use results from the investigation to prevent scaldcoating failure at elevated temperatures; and (c) identify conditions that lead to more damage-tolerant coatings and scales that are amenable to legitimate synthesis routes. The paper presents experimental data on microstructural characteristics of alumina scales that have been thermally developed on several Fe-based alumina-forming intermetallic alloys. In addition, adhesion data developed on the scales are presented, along with determinations of strain from data obtained by ruby fluorescence.

A new technology for drilling stone materials without water and dust is introduced in the present paper. The state of the new drilling technique, the advantages of the technique and its application fields were discussed in detail. Conceptual FormulationThe necessity to lay supply lines such as aerating pipes, electric mains, ventilation pipes in buildings requires drilling of holes in different construction materials. Environment runs and the compulsion to safe money lead to new drilling technologies. Wet Core Drilling MethodWith the current wet core drilling-method it is possible to drill through almost every construction material at the building site.