Dependence of brittle-to-ductile transition on crystallographic direction in diamond turning of single-crystal silicon

Autor(es)

Jasinevicius, R. G. ^[1] ; Duduch, J. G. ^[1] ; Montanari, L. ^[1] ; Pizani, P. S. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, EESC, Dept Eng Mec, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Fis, BR-13560 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF EN; v. 226, n. B3, p. 445-458, MAR 2012.
• Citações Web of Science: 13

Resumo

The objective of this paper is to show the dependence relationship between the crystallographic orientations upon brittle-to-ductile transition during diamond turning of monocrystalline silicon. Cutting tests were performed using a -5 degrees rake angle round nose diamond tool at different machining scales. At the micrometre level, the feedrate was kept constant at 2.5 micrometres per revolution (mu m/r), and the depth of cut was varied from 1 to 5 mu m. At the submicrometre level, the depth of cut was kept constant at 500 nm and the feedrate varied from 5 to 10 mu m/r. At the micrometre level, the uncut shoulder generated with an interrupted cutting test procedure provided a quantitative measurement of the ductile-to-brittle transition. Results show that the critical chip thickness in silicon for ductile material removal reaches a maximum of 285 nm in the {[}100] direction and a minimum of 115 nm in the {[}110] direction, when the depth of cut was 5 mu m. It was found that when a submicrometre depth of cut was applied, microcracks were revealed in the {[}110] direction, which is the softer direction in silicon. Micro Raman spectroscopy was used to estimate surface residual stress after machining. Compressive residual stress in the range 142 MPa and smooth damage free surface finish was probed in the {[}100] direction for a depth of cut of 5 mu m, whereas residual stresses in the range 350 MPa and brittle damage was probed in the {[}110] direction for a depth of cut of 500 nm. (AU)

• Processo FAPESP: 07/56463-8 - Efeitos de pressão hidrostática e não hidrostática nas propriedades estruturais e dinâmicas de sólidos cristalinos
• Beneficiário: Paulo Sergio Pizani
• Modalidade de apoio: Auxílio à Pesquisa - Regular