Materials & Raw Stock

The trend toward developing finer and finer carbide grains continues. The author looks at recent developments in the production of nanosized tungsten-carbide grains, which are smaller than 0.2 microns in diameter. Though not used widely at present for the production of cutting tools, some predict that will change as the technology evolves.

High-silicon aluminum--aluminum that consists of at least 11.8 percent silicon--has qualities such as lightness and strength that appeal to automakers. The abrasives nature of the material, however, makes it difficult to machine. The author offers suggestions for milling, tapping, drilling, turning and grinding high-silicon aluminum.

Dry milling and turning grow in popularity day by day, but dry drilling is nanother matter. Because of the nature of drilling, it's more difficult to nperform this operation without coolant. Still, progress is being made, nthanks to research and more sophisticated coatings.n

Researchers from Lehigh University report the results of drilling tests conducted using sintered steel samples. The samples were prepared using different machinability-improving additives. The results showed that sintered steel with low-alloy steel and resulferized sintered steel are nearly as machinable as wrought steel.

Machining ceramics is considered a difficult and costly operation. With the growing use of ceramics, shops are anxious to find cost-effective ways to work with the materials. This article discusses attempts by researchers to achieve maximum metal-removal rates without damaging the workpiece.

Tantalum and Niobium are important components in the composition of carbide tools. They are also among the most expensive. This article explores how recent trends in metalcutting and tool usage will effect the supply of these two components.

This article traces the changes in countersink design and materials that have been made to satisfy the demands of the aerospace industry. The advantages and disadvantages of different types of modern countersinks are discussed.

Stainless steel is one of the more difficult materials to cut. This article discusses the problems that can occur when turning various types of stainless steels, the reasons for these problems and ways to avoid them. Advice is given on diagnosing problems based on tool-wear patterns. The article also suggests ways to correct problems once they are discovered.

When shops crank up the speed, they have to be prepared for the consequences, even if they're milling "easy-to-machine" aluminum.

Improvements in cermet and ceramic inserts have made them a good choice for high-speed milling. This article describes how the compositions and designs of these newer inserts make them tough enough to withstand the punishment of a milling operation while maintaining the hardness that makes them wear-resistant.

This article describes the shapes and sizes of diamond particles produced through standard manufacturing processes. The uses for these different types of particles are also explained, with an emphasis on particles used in superfinishing powders and slurries.

Cermet inserts have evolved into cutting tools capable of finish-turning steel reliably at high speeds. This article traces the developments that have led to modern cermets and describes the properties that enhance the performance of these tools. The development of coatings for cermets is also covered.