Development of Aluminum Alloys with High Strength and High elasticity Controlled Structurally by Solidification Processing.
| Project/Area Number |
04402048
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属加工(含鋳造)
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
KAMIO Akihiko Tokyo Inst.of Tech., Depart.of Eng., Professor, 工学部, 教授 (60016524)
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| Co-Investigator(Kenkyū-buntansha) |
TEZUKA Hiroyasu T.I.T., Depart.of Eng., Research Associate, 工学部, 助手 (40180070)
SATO Tatsuo T.I.T., Depart.of Eng., Associate Professor, 工学部, 助教授 (90126318)
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| Project Period (FY) |
1992 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥33,400,000 (Direct Cost: ¥33,400,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥9,300,000 (Direct Cost: ¥9,300,000)
Fiscal Year 1992: ¥22,600,000 (Direct Cost: ¥22,600,000)
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| Keywords | Al-Liallys / Al-Mg alloys / Squeeze Casting / Composite materials / Interface Reaction / Precipitation Hardening / Residual Stress / SiC whisker / SiCウイスカー / Al-Li-Cu合金 / ウイスカー / 高圧凝固 / 結晶粒微細化 / 複合析出 / 凝固組織 |
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| Research Abstract |
On the Al-Li and the Al-Mg alloys composites reinforced with SiC whiskers fabricated by the squeeze casting, the preparation technique was established and the relation between the properties and the structure control was clarified for the purpose of the development of aluminum alloys with the low density, high strength and elasticity.
It was found that the low concentration region of Li or Mg shaped along the infiltration path of matrix alloy melts in the composites was formed during squeeze casting by the reaction between the Li or Mg solute atom in aluminum matrix melts and the SiO_2 presented in the SiC whisker preform. Sound composite ingots without the Li or Mg depleted region was obtained by using the fabrication method specially designed so as to through out of the depleted region for outside of composite ingots.
The remarkable age hardening of the SiCw/Al-Li alloys composites was obtained, despite of no or slight age hardening of the other age hardenable aluminum alloys composite
… More
s. The prominent age hardening of Al-Li based alloy composites was obtained by the precipitation of metastable delta' and/or T_1 phases. The T_1 phase in the composites was precipitated preferentially on the dislocations of high density generated during quenching after the solution treatment. In the SiCw/Al-Li alloys composites, the elastic modulus and yield strength were increased linearly with increasing the SiC whisker volume fraction.
In the SiCw/Al alloy composites, the tensile yield strength was decreased and the compressive yield strength was increased by the tensile residual stress induced during cooling from the solution treatment temperature. The magnitude of the averaged tensile residual stress measured by X-ray diffraction method in the composites was strongly dependent on the yield strength of the matrix in composites. The tensile yield strength of the composite restored to room temperature after cooled into liquid nitrogen temperature was significantly increased by the double effects due to both the decrease of the tensile residual stress and the increase of the average dislocation density in the matrix of the composite.
In the Al-Mg alloy composite contained a large amount of the SiO_2 phase, the good connection at the interface caused by the formation of the MgAl_2O_4 as the main reaction phase at the whisker/matrix interface was achieved. The control of the connecting strength at the interface and the improvement of the yield strength for the composite materials are obtained by the control of the kind of the interface reaction products and the thickness due to the proper choice of the amounts of SiO_2 phase. Less
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Report
(4 results)
Research Products
(2 results)
