Abstract

A nanocrystalline(NC) bulk glass Zr55Al10Cu30Ni5(at%) which contains nano-scale crystals embedded uniformly in a glassy matrix has both high tensile strength of 1.7 GPa and high ductility. It is therefore expected to find practical application in machines and structures. The fatigue crack propagation behavior of the NC bulk glass was examined. The threshold stress intensity factor range ΔKth was about 0.9 MPa\sqrtm, and the fatigue fracture toughness Kfc was about 13 MPa\sqrtm. Fatigue crack propagation rate da⁄dn was approximately proportional to ΔK2. No significant difference in da⁄dn between the NC glassy alloy and single phase amorphous alloys in literature was seen when they are compared on the basis of ΔK divided by Young’s modulus E. The da⁄dn values were nearly the same as those for steels with the same tensile strength level. The da⁄dn values were larger than those for low strength steels, Al alloys and Ti alloys in the low da⁄dn range. When compared with the effective stress intensity factor range ΔKeff divided by E, the da⁄dn values for crystalline alloys were almost coincident with those under different stress ratios for the NC glassy alloy. This indicates that the da⁄dn values for the NC glassy alloy can be estimated on the basis of the da⁄dn data for crystalline alloys.

Full Text
Paper version not known

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 call

Disclaimer: 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.