Variation of contact angles with temperature and time in the Al-Al{sub 2}O{sub 3} system

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Metallurgical Transactions, B

OSTI ID:212187

Jung, W; Kim, D Y ^[1]; Song, H; Park, S W ^[2]

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1. Seoul National Univ. (Korea, Republic of). Dept. of Inorganic Materials Engineering
2. Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Div. of Ceramics

The contact angles of liquid Al on polycrystalline Al{sub 2}O{sub 3} determined by the conventional sessile drop method were obtuse ({approximately} 120 deg) up to 900 C but decreased rapidly at 1,000 C. When the molten Al was squeezed through a narrow orifice and dropped onto the substrate, the contact angle at 900 C was 77 deg and decreased linearly with temperature. At 1,000 C and 1,100 C, the contact angles decreased slowly with holding times up to 50 and 6 hours, respectively. At 1,200 C, the contact angle also decreased with holding time up to 40 minutes, after which it oscillated, resulting in a ring pattern on the substrate. The structural change of the Al{sub 2}O{sub 3} substrate surface is suggested to be an important variable that determines the wetting behavior of the Al-Al{sub 2}O{sub 3} system.

• OSTI ID: 212187
• Journal Information: Metallurgical Transactions, B, Journal Name: Metallurgical Transactions, B Journal Issue: 1 Vol. 27; ISSN MTTBCR; ISSN 0360-2141
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ALUMINIUM OXIDES
DROPLETS
INCIDENCE ANGLE
LIQUID METALS
MORPHOLOGICAL CHANGES
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
WETTABILITY