Alpha-Case Reduction Mechanism of Titanium Powder-Added Investment Molds for Titanium Casting

Autor:	Young-Jig Kim, Bong-Jae Choi, Seul Lee
Rok vydání:	2014
Předmět:	Materials science Mechanical Engineering Metallurgy chemistry.chemical_element Microstructure Hardness Casting Titanium powder chemistry Mechanics of Materials General Materials Science Contact area Alpha case Curing (chemistry) Titanium
Zdroj:	Journal of Materials Engineering and Performance. 23:1415-1423
ISSN:	1544-1024 1059-9495
DOI:	10.1007/s11665-013-0859-6
Popis:	The surface alpha-case reaction of Ti casting using Ti powder-added investment molds was investigated. During the curing procedure, Ti powders (0, 10, and 50 mass%) were mixed with three types of investment mold materials (Al2O3, ZrSiO4, and ZrO2) to form an interstitial TiO2 phase, which is an alpha-case reaction compound. The microstructure and surface hardness profiles of Ti castings with Ti powder-added investment molds indicated that the alpha-case thickness was significantly reduced from approximately 350 to 50-100 μm, and a remarkable reduction in the maximum micro-Vickers hardness value of the Ti casting surface was also achieved. As observed from the experimental results, the alpha-case reduction mechanism suggested that the phase transformation from TiO2 to TiO not only acts as an effective barrier to O diffusion, but also reduces Al, Si, and Zr concentrations at the casting surface. This reduction might be caused by contact area reduction between the Ti powder-added investment molds and the Ti melts.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c97666596696df4616eeef9f94fec372 https://doi.org/10.1007/s11665-013-0859-6 Zobrazit plný text záznamu Full text from SpringerLink