Tool vibration in internal turning of hardened steel using cBN tool
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The machining of hardened materials with hardness over 45 HRC has been an alternative to grinding since the 1970s, with the commercial availability of cubic boron nitride (cBN) and ceramic tools. However, the low toughness of these types of tool materials makes them very sensitive to damages caused by vibrations, which are critical for operations like internal turning, where the tool resembles a cantilever beam and therefore is susceptible to large deflections. This work aims to contribute to the study of tool performance in internal turning of long holes in hardened AISI 4340 steel in finishing conditions. Different machining conditions, two different tool holders (steel and carbide), and several tool overhangs were tested. The surface finish, acceleration (vibration) signals, and tool wear of cBN inserts were evaluated. The results show that vibration and the material of the tool holder may play a secondary role in the surface finish for stable turning, but the use of carbide tool holders makes the process stable for longer tool overhangs. Moreover, when the cutting becomes unstable, surface roughness is increased severely.
KeywordsVibration Boring Hard machining Hardened steel cBN
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- 3.Huddle D (2001) New hard turning tools and techniques offer a cost-effective alternative to grinding. Tooling Prod Mag 80:96–103Google Scholar
- 10.Altintas Y (2000) Static and dynamic deformations in machining. In: Altintas Y (ed) Manufacturing automation: metal cutting mechanics, machine tool vibrations, and CNC design. Cambridge University Press, New York, pp 65–121Google Scholar
- 20.Coromant S (2015) Turning tools. Sandvik, SandvikenGoogle Scholar
- 21.Diniz AE, Marcondes FC, Coppini NL (2013) Avarias e Desgastes da Ferramenta. In: Diniz AE, Marcondes FC, Coppini NL (eds) Tecnologia da Usinagem dos Materiais, 8th edn. Artilber, São Paulo, pp 107–118Google Scholar