Pressureless Infiltration of Ceramics by Molten Metals

摘要

Pressureless infiltration of molten metals into ceramics is perhaps the most cost- effective approach to liquid-metal processing of metal-matrix composites. Two approaches are currently being investigated for their respective pressureless infiltration potential. A 'carrier oxide' approach to infiltration relies on the use of a intermediary liquid oxide which carriers the liquid metal into the capillary channels of the porous ceramic. The effectiveness of this approach was discovered by understanding the nature of wetting and spreading in copper-oxygen and copper-titanium alloy liquids in contact with alumina substrates. Aluminum oxide, a relatively cheap reinforcing material, does not develop an interface with liquid aluminum, but titanium readily wets aluminum oxide. Titanium-coated aluminum oxide surfaces are energetically conducive to the pressureless infiltration of liquid aluminum. Results from the above two approaches are discussed in detail in the following sections.