Artigo de peri??dico
Mechanical characterisation and machining evaluation of ceramic cutting tools functionally graded with six layers
Registro en:
0272-8842
10
46
10.1016/j.ceramint.2020.03.048
0000-0003-1371-7521
91.38
83.00
Autor
BERTOLETE, M.
BARBOSA, P.A.
ROSSI, WAGNER de
FREDERICCI, C.
MACHADO, I.F.
Resumen
Functionally graded materials (FGMs) are composites graded in one or more directions by the mean volume
fraction variation of their constituents in a continuous or stepwise design. The objective of this study is to apply
the FGM concept to ceramic cutting tools to widen its application range. Thus, two cutting tool materials were
selected: cemented carbide, owing to its higher toughness, and alumina-based ceramic, owing to its high wear
resistance at elevated temperatures. Ceramics based on alumina were functionally graded with cemented carbide
and sintered using the spark plasma sintering technique. The thermal residual stresses were predicted; additionally,
the microstructure, relative density, and Vickers hardness and fracture toughness for the alumina
layer were evaluated, and flexural strength and machining tests were conducted. From the results, cracks were
not observed in the microstructure and full density was obtained. In general, the hardness and fracture toughness
values were close to those in the literature. A flexural strength improvement of at least 50% on FGM samples was
observed in comparison to homogeneous ceramic ones. The FGM cutting tools supported approximately 1000 N
of machining force without catastrophic failure when turning martensitic stainless steel into a conventional
lathe. The values of surface roughness (Ra and Rz) agree with those in the literature under similar cutting and
geometry conditions. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) Funda????o de Amparo ?? Pesquisa e Inova????o do Esp??rito Santo (FAPES) FAPESP: 10/00683-2 CNPq: 472145/2010-0; 405707/2013-4 FAPES: 083/2019