ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The strength and ductility of an Al-6 wt % Zn-1.2 wt % Mg alloy at low temperatures have been investigated by varying the grain size, the amount of grain-boundary precipitate and the nature of the precipitates in the matrix. Pronounced grain-boundary embrittlement has been observed at temperatures below — 100° C in alloys age-hardened by GP zones and especially in coarse-grained alloy specimens, but was not observed in over-aged specimens. From the condition for plastic instability related to the grain-boundary micro-cracking, the temperature and structure dependences of the ultimate tensile properties are expressed by; (σ i − σo)/σi=ε u/n + C, where σ i is the instability stress (true ultimate tensile strength), σ 0 the 0.2% proof stress, ε u the uniform elongation, n a constant found to be about 1/2 and C a constant related to the work-hardening rate of the matrix.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00544723
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