As-cast titanium aluminides microstructure modification
Two cast <FONT FACE="Symbol">g</font> titanium aluminides, Ti47Al and Ti50Al (at. %), were obtained by arc melting under an argon atmosphere. The as-cast microstructure modification by annealing under protective argon atmosphere and hot isostatic pressing (HIP) was analysed by...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
1999-07-01
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| Series: | Materials Research |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14391999000300013 |
| _version_ | 1819021597201137664 |
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| author | A. Duarte F. Viana Henrique M.C.M. Santos |
| author_facet | A. Duarte F. Viana Henrique M.C.M. Santos |
| author_sort | A. Duarte |
| collection | DOAJ |
| description | Two cast <FONT FACE="Symbol">g</font> titanium aluminides, Ti47Al and Ti50Al (at. %), were obtained by arc melting under an argon atmosphere. The as-cast microstructure modification by annealing under protective argon atmosphere and hot isostatic pressing (HIP) was analysed by optical and scanning electron microscopy with microanalysis facilities. As-cast structures presented strong microsegregations, being composed of primary <FONT FACE="Symbol">a</font> dendrites (with low Al content), which transformed into lamellar <FONT FACE="Symbol">a</font>2 + <FONT FACE="Symbol">g</font> during solid state cooling, and interdendritic <FONT FACE="Symbol">g</font> phase (with high Al content). Annealing in the <FONT FACE="Symbol">a</font> + <FONT FACE="Symbol">g</font> field was responsible for a partial reduction of microsegregation, a decreasing of the volume fraction of <FONT FACE="Symbol">a</font>2 + <FONT FACE="Symbol">g</font> lamellar dendrites, an increasing of <FONT FACE="Symbol">g</font> volume fraction and the occurrence of a small fraction of <FONT FACE="Symbol">a</font>2 particles and plates in some of the <FONT FACE="Symbol">g</font> grains. Annealing in the <FONT FACE="Symbol">a</font> field at 1400 °C for one hour was insufficient to eliminate the as-cast microstructure in the Ti50Al alloy and produced large equiaxed lamellar colonies of <FONT FACE="Symbol">a</font>2+<FONT FACE="Symbol">g</font> in the Ti47Al alloy. HIP in the <FONT FACE="Symbol">a</font> + <FONT FACE="Symbol">g</font> field (to avoid excessive grain growth) was responsible for microstructure modifications similar to the ones obtained by heat treating under similar soaking conditions. |
| first_indexed | 2024-12-21T04:09:38Z |
| format | Article |
| id | doaj.art-17e17f2840dd40c29c338803f96b8500 |
| institution | Directory Open Access Journal |
| issn | 1516-1439 |
| language | English |
| last_indexed | 2024-12-21T04:09:38Z |
| publishDate | 1999-07-01 |
| publisher | Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) |
| record_format | Article |
| series | Materials Research |
| spelling | doaj.art-17e17f2840dd40c29c338803f96b85002022-12-21T19:16:29ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14391999-07-012319119510.1590/S1516-14391999000300013As-cast titanium aluminides microstructure modificationA. DuarteF. VianaHenrique M.C.M. SantosTwo cast <FONT FACE="Symbol">g</font> titanium aluminides, Ti47Al and Ti50Al (at. %), were obtained by arc melting under an argon atmosphere. The as-cast microstructure modification by annealing under protective argon atmosphere and hot isostatic pressing (HIP) was analysed by optical and scanning electron microscopy with microanalysis facilities. As-cast structures presented strong microsegregations, being composed of primary <FONT FACE="Symbol">a</font> dendrites (with low Al content), which transformed into lamellar <FONT FACE="Symbol">a</font>2 + <FONT FACE="Symbol">g</font> during solid state cooling, and interdendritic <FONT FACE="Symbol">g</font> phase (with high Al content). Annealing in the <FONT FACE="Symbol">a</font> + <FONT FACE="Symbol">g</font> field was responsible for a partial reduction of microsegregation, a decreasing of the volume fraction of <FONT FACE="Symbol">a</font>2 + <FONT FACE="Symbol">g</font> lamellar dendrites, an increasing of <FONT FACE="Symbol">g</font> volume fraction and the occurrence of a small fraction of <FONT FACE="Symbol">a</font>2 particles and plates in some of the <FONT FACE="Symbol">g</font> grains. Annealing in the <FONT FACE="Symbol">a</font> field at 1400 °C for one hour was insufficient to eliminate the as-cast microstructure in the Ti50Al alloy and produced large equiaxed lamellar colonies of <FONT FACE="Symbol">a</font>2+<FONT FACE="Symbol">g</font> in the Ti47Al alloy. HIP in the <FONT FACE="Symbol">a</font> + <FONT FACE="Symbol">g</font> field (to avoid excessive grain growth) was responsible for microstructure modifications similar to the ones obtained by heat treating under similar soaking conditions.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14391999000300013titanium aluminidesmicrostructureheat treatment |
| spellingShingle | A. Duarte F. Viana Henrique M.C.M. Santos As-cast titanium aluminides microstructure modification Materials Research titanium aluminides microstructure heat treatment |
| title | As-cast titanium aluminides microstructure modification |
| title_full | As-cast titanium aluminides microstructure modification |
| title_fullStr | As-cast titanium aluminides microstructure modification |
| title_full_unstemmed | As-cast titanium aluminides microstructure modification |
| title_short | As-cast titanium aluminides microstructure modification |
| title_sort | as cast titanium aluminides microstructure modification |
| topic | titanium aluminides microstructure heat treatment |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14391999000300013 |
| work_keys_str_mv | AT aduarte ascasttitaniumaluminidesmicrostructuremodification AT fviana ascasttitaniumaluminidesmicrostructuremodification AT henriquemcmsantos ascasttitaniumaluminidesmicrostructuremodification |