Abstract
In the present study, the fatigue crack growth (FCG) behavior of short surface cracks in a fine-grained cemented carbide with a length of less than 1 mm was investigated. The rotating bending and the four-point bending fatigue tests were carried out at stress ratios of R = −1 and R = 0.1 (R = maximum stress/minimum stress). It was found that a short surface crack had a longer stable fatigue crack growth area than a long through-thickness crack; the FCG behaviors of the two types of crack are clearly different. Furthermore, the FCG path of short surface cracks was investigated in detail to study the interaction between fatigue cracks and microstructures of the cemented carbide such as WC grains and the Co phase. At a low Kmax (Kmax = the maximum stress intensity factor), it was found that fatigue crack growth within WC grains is difficult because of a small driving force; instead, crack growth is along the brittle WC/WC interface. On the other hand, at a high Kmax, WC grain breakage often occurs, since the driving force of FCG is large, and the fatigue crack grows linearly.
Highlights
Cemented carbides are widely used for cutting tools, dies, mechanical parts, and so forth [1], because of their superior abrasive wear resistance to tool steels
Rotating and four-point bending fatigue tests were conducted on a fine-grained WC-Co
Rotating and four-point bending fatigue tests were conducted on a fine-grained WC-Co cemented cemented carbide to investigate the fatigue crack growth (FCG) behavior of short surface fatigue cracks in detail
Summary
Cemented carbides are widely used for cutting tools, dies, mechanical parts, and so forth [1], because of their superior abrasive wear resistance to tool steels. WC-Co alloys have superior mechanical properties and are highly versatile and widely used [2]. The mechanical properties of cemented carbides are intermediate between those of brittle materials, such as ceramics and cermets, and ductile materials such as tool steels. The extent of the brittleness increases as the Co content decreases and the WC grain size decreases. As the Co content increases, the toughness of the material increases, but the hardness decreases. As the WC grain size increases, the toughness of the material increases, but the hardness decreases [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
