Fracture behaviour of nc-TiAlN/a-Si3N4 nanocomposite coating during nanoimpact test

• Cyclic nanoimpact tests were carried on nc-TiAlN/a-Si3N4 nanocomposite, TiN and multilayered TiN/nanocomposite (NC) coatings to evaluate their resistance to fracture under cyclic impact loads. Fracture behaviour of the coatings was ascertained from fracture probability obtained from time-depth curves and focus ion beam milling images of resulting indentation impressions. TiN coating mainly showed intercolumnar cracks while the other coatings showed other modes of cracking, that is, lateral, inclined, bending, edge cracks, during testing. The performance ranking of the coatings, TiN > TiN/NC > nc-TiAlN/a-Si3N4, is linked to their β0 value, representing relative indentation depth of the coating-substrate composite hardness system at which the fractional hardness improvement equal to 50% of the maximum is retained and also their corresponding microstructure. Apart from enabling prediction of fracture resistance of the coatings, these studies provide useful insights into design and selection of coating materials for targeted machining applications. © 2016 Institute of Materials, Minerals and Mining

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

Nyckelord

Composite coatings; Cracks; Fracture; Fracture mechanics; Hardness; Ion beams; Nanocomposites; Tin; Titanium compounds; Titanium nitride

Composite hardness; Fracture probability; Nano-composite coating; Nanoimpact; Performance rankings; Relative indentation depths; TiAlN; TiAlSiN

Coatings

Production Technology

Produktionsteknik

Manufacturing and materials engineering

Produktions- och materialteknik

Publikations- och innehållstyp

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