Determination of the creep crack initiation properties using pre-cracked small punch tests. (December 2016)

• Record Type: Journal Article
• Authors: Alegre, J.M.; Cuesta, I.I.; Rodriguez, C.; Belzunce, F.J.
• Is Part Of: Theoretical and applied fracture mechanics. Volume 86:Part A(2016)
• Page Start: 39
• Page End: 44
• Publication Date: 2016-12
• Subjects: Creep crack initiation -- Small punch tests -- Notches; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2016.08.022
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: The use of p-SPCT is analyzed as an alternative method to obtain the CCI time. Initial crack-like notch was created by means of a laser micro-cutting technique. The definition of an equivalent load for p-SPCT was seen to be a good methodology. The influence of temperature and material on the parameter still remains to be investigated. Abstract: The use of pre-cracked small punch creep test specimens ( p-SPCT ) is analyzed in this paper as an alternative method to obtain the Creep Crack Initiation ( CCI ) time in those cases where there is not enough material to use CT specimens. The material selected was an AZ31B magnesium alloy. The geometry of the specimens used was 10 × 10 mm square with a thickness of 0.5 mm. An initial crack-like notch was created in the SPT specimens by means of a laser micro-cutting technique. Conventional compact specimens ( CT-20 ) were tested at T = 150 °C as a reference for CCI determination. The definition of an equivalent load for p-SPCT was seen to be a good methodology, and a λ parameter was defined to convert the p-SPCT to an equivalent C ( T ) load that produces the same CCI time. The influence of temperature and material on the λ parameter still remains to be investigated.