| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
The composition of the plloys in this investigation are Al-Li alloys containing 4 Wt% Li with or without 1 wt% Zr. The alloys rapidly quenched from the melt into continuous ribbons using jet casting process by single and twin rolls. these ribbons were mechanichally comminuted to fine powder and then consolidated into bulk compacts by vacuum hot pressing and hot extrusion to wires of 2.0mm in diameter(20:<iota> extrusion tatio). These wires were further drown to wires of 1.5 and 1.6mm in diameters.
The were specimes were age-treated in the following;(a) as-drown,(b) pre-aged, 500゜Cx2hrs,(c) single-aged, 190゜Cx16hrs,(d) double-aged, 500゜Cx2hrs+190゜Cx16hrs,(e) doule-aged, 500゜Cx72hrs+190゜Cx16hrs.
The age-treated specimens were examind by a transmission electron microscope in order to clarify the nature, size and distribution of precipitatrs. It was found that double-ageing is very effective to the formation of composite precipitates, which is a continuous envelope of <delta>'Al_3Li surrounding the <alpha>'-Al_3Zr. The present investigation has shown that the enganced mechanical properties that were obtained were mainly due to the promoted precipitaition of composite precipitete.
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