Metallographic and Magentic Properties of a Yamato Iron Meteorite─Yamato-75-105
A Yamato iron meteroite, Yamato-75-105, examined chemically, metallographically and magnetically, has revealed that the major elements of the metal base of this iron meteorite are 5.65% Ni, 1.0% P, and 0.52% Co, in addition to Fe occupying the most parts. From the chemical composition and the micros...
| Main Authors: | , , |
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| Format: | Report |
| Language: | English |
| Published: |
National Institute of Polar Research
1976
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| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=588 http://id.nii.ac.jp/1291/00000588/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=588&item_no=1&attribute_id=18&file_no=1 |
| Summary: | A Yamato iron meteroite, Yamato-75-105, examined chemically, metallographically and magnetically, has revealed that the major elements of the metal base of this iron meteorite are 5.65% Ni, 1.0% P, and 0.52% Co, in addition to Fe occupying the most parts. From the chemical composition and the microstructure, this iron meteorite can be classified as a reheated hexahedrite, i. e. a Ni-poor ataxite. An "ablation zone" about 2mm in thickness on the flat surface indicates an extensive reheating on entry into the earth's atmosphere although traces of the original single-crystal features remain. Within the matrix of kamacite (95% Fe and 5% Ni) composition, Fe-Ni phosphide (schribersite 75% Fe, 10% Ni and 15% P) grains are enveloped by high-P kamacite of α-phase (91% Fe, 7% Ni and 2% P). These structures suggest that this meteorite specimen was reheated to above 1000℃. The acicular grain structure of the kamacite matrix indicates a rapid cooling rate after the reheating. Both metallographic and magnetic analyses have consistently revealed the above-mentioned conclusion. |
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