John Herbert Frey

Cryogenic Machining with Brittle Tools and Effects on Tool Life

With the current popularity of finish hard turning, the need for improved productivity and tool life is of significant importance to manufacturers. The present work explores the effects of cryogenic coolants in machining hardened materials, from an industrial perspective, with emphasis on productivity and tool life improvement, environmental effects, as well as reliable performance characteristics for brittle tools. Both alumina ceramic (Al2O3) and polycrystalline cubic boron nitride (PCBN) tools show significant tool life improvement in cryomachining of hard ferrous materials, such as 52100 bearing steel and A2 tool steel. Significant productivity gains have also been observed in cryogenic machining of WC-Co rolls with polycrystalline diamond (PCD) tools. The enhanced performance of cryomachining is attributed to more efficient heat removal from the cutting insert, as well as reduction in thermal softening of the cutting tools at higher temperatures.

Design of a new silicone surfactant for flexible slabstock polyurethane foam

Requirements for silicone surfactants for flexible slabstock polyurethane foam are varied and demanding and consideration must be given to new requirements for high water formulations, low density formulations, emulsification of high water levels into different types of polyols, and mixing for continuous and discontinuous foam manufacturing processes. The demands of these formulations and processes are reviewed. Surfactant molecular structure versus performance results are presented in formulations typical of those used today by the slabstock industry. A new surfactant, DABCOO DC5188, has been developed to meet the diverse requirements of these systems. The performance of this surfactant is reported.

Accelerated and improved carburising with MFC controlled nitrogen-methanol atmospheres

Abstract The ability to produce high quality and consistant carburised parts requires precise control of the carbursing atmosphere. The use of mass flow controllers (MFCs) is described as a means to regulate the furnace atmosphere composition as well as to improve quality of the heat treated parts by the use of a consistent atmosphere. Furthermore, the increasing productivity by the use of accelerated carburising (ACP) and MFCs is reported.