Bajalan, M.R. (1992) Machining of steels with ceramic tools. PhD thesis, University of Warwick.

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Abstract

Five different types of ceramic tools of varying chemical compositions, KO60 (oxide based ceramic), KO90 (mixed ceramic), KYON2500 (SiC whisker reinforced) and KYON2000 and KYON3000 (nitride based ceramics) were used to machine three different grades of steel, namely EN8 (plain carbon steel), D2 tool steel (hardened steel) and EN24 (alloy steel) under various cutting conditions. Throughout the experiments various cutting speeds were used (50 - 700 m/min) for each of the cutting tools and work materials under investigation. The feed rate and depth of cut were kept fixed. The objective of these tests was to assess the optimum cutting conditions of each grade of ceramic tools used when machining steels. In all cases, the worn tools were examined to identify wear mechanisms and to determine how the wear was affected by the nature of the different workpiece, tool materials and variables such as cutting speeds. Furthermore, in order to understand the condition at the tool/chip interface cutting forces and surface finish were also measured.
The results showed that the tools failed mainly by flank face wear. The wear mechanism analyses suggested that attrition, diffusion and plastic deformation controlled the tool life. At slower speeds, attrition has been the dominant wear mode, where as at higher speeds, evidence of diffusion and plastic deformation was the dominant wear mechanism.
From study of the microstructure of ceramic tools, it was found that materials having smaller grain sizes gave the best tool life. It was also found that the large glass islands of nitride based ceramics enhanced attrition and diffusion wear resulting in a shorter tool life.

Item Type:	Thesis (PhD)
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Library of Congress Subject Headings (LCSH):	Metals -- Mechanical properties, Ceramics -- Mechanical properties
Official Date:	October 1992
Dates:	Date Event October 1992 Submitted
Institution:	University of Warwick
Theses Department:	Department of Engineering
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Jawaid, Ashraf
Extent:	236 leaves : illustrations
Language:	eng

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