Abstract
Magnesium-calcium alloy-based composites reinforced with vapor grown carbon fibers (VGCFs) are supposed to possess satisfactory high-temperature applications. However, poor wettability of magnesium with carbon fiber is a technical problem encountered in fabrication of the composites. In order to cover the wetting problem, wetting behavior of magnesium alloys on graphite sheet, pure nickel, and nickel coated graphite sheet were investigated using sessile drop method. The graphite was non-wetting by both Mg-5Al alloy and Mg-5Al-3Ca alloy with contact angles about 120°. The droplet of magnesium alloys on nickel plate spread rapidly. Contact angle of Mg-5Al-3Ca alloy decreased from about 94° to 43°. Wettability of magnesium alloys on nickel coated graphite sheet was improved through the dissolution of nickel into the liquid magnesium alloy. Calcium addition showed negative effect on contact angle of nickel substrate, and also slightly hindered the spread of magnesium alloy droplet on nickel coated graphite sheet.
