Surface Finishing & Coating

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.

High-performance aluminum-alloy workpieces are prone to residual stresses that can lead to part distortion. This article reviews the milling tools and practices that affect these stresses. Some tools and practices alleviate the stress, while others allow the machinist to mill the part without adding more stress.

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.

The development of the CVD thick-film diamond process has made it possible to produce tools that can machine abrasive work materials without losing their cutting edge. In this article, the technology for producing the diamond film and the brazing of these thick-film chips onto inserts is described.

To meet their customers' demands, mold and die shops are milling hardened steels at high speeds. This article discusses the use of coated carbide inserts to handle the heat generated by these operations. Specifically, the article talks about recently developed aluminum-titanium-nitride coatings, which reportedly are much more stable at elevated temperatures than other coatings.

This article reviews the nomenclature that toolmakers use to identify inserts. Both ANSI and ISO codes are described character by character. A chart lists all of the possible choices for each position in the code and what each code letter or number signifies.

It took years to perfect, but manufacturers finally found a way to economically coat carbide inserts with a diamond film. This article describes the coating process and looks at that companies that are offering diamond-coated tools, the companies that are coating tools for other manufacturers and the companies that are supplying coating equipment. Thick-film diamond is also discussed.

A clear and intact substrate surface is important to the success of a coating deposited on a carbide insert. This article looks at the surface problems and contamination, introduced by the insert manufacturing process, that the coating company or insert user must correct before the insert is ready to be coated.

Ion implantation bombards a tool's surface with accelerated metal ions. According to this article, the process increases tool life and the performance of tool coatings. Two theories explaining why the process works are also discussed.