Use of Ca in metal matrix composites (MMC) allows for incorporation of small and large amounts of ceramic (e.g. rutile TiO.sub.2) into the metal (Al, or its alloys). Calcium remains principally out of the matrix and is part of a boundary layer system that has advantages for integrity of the MMC. Between 0.005 and 10 wt. % calcium (Ca) may be included, and more than 50 wt. % of rutile has been shown to be integrated. Rutile may therefore be used to reduce melt loss due to calcium from an aluminum or aluminum alloy melt.

A method of reducing entrained aluminum oxides in aluminum castings. The method comprises preheating a furnace charge to remove moisture and contaminants. The furnace charge is then coated on all free surfaces with a layer of flux. Subsequently the furnace charge is melted in a furnace to form a melt bath of liquid aluminum suitable for casting. The flux layer removes the naturally occurring oxide film from the furnace charge surface as well as provides a cover flux to protect the melt bath from oxidation.

A method for preparing an aluminum-zirconium-boron alloy and synchronously preparing a cryolite is provided. The method includes the following steps: Step A: placing aluminum in a reactor, heating the reactor to 700-850 degrees centigrade, and adding a mixture consisting of fluorozirconate and fluoborate in a molar ratio of x: y into the reactor; Step B: stirring the reactants for 4-6 hours and extracting the upper molten liquid to obtain a cryolite, wherein the lower substance is an aluminum-zirconium-boron alloy, and aluminum is added in an excess amount. The method provided herein for preparing an aluminum-zirconium-boron alloy which is mild in reaction condition, easy to control and simple in technical flow can prepare a high-quality product through a complete reaction, besides, the use of the synchronously prepared low molecular ratio cryolites (KF.AlF.sub.3 and NaF.AlF.sub.3) in the aluminum electrolysis industry can achieve a proper electrical conductivity.

A manufacturing method can obtain Al-based particles. A particle-dispersed molten salt (an example of an Al base material), in which Al-based particles (liquid phase) are dispersed in molten salt, can be obtained by bringing Al-based foil into contact with molten salt. Through particle-dispersed molten salt, for example, Al-based powder (an example of Al base material) composed of Al-based particles (solid phase) can be efficiently or easily obtained. By classifying Al-based particle groups, Al-based powder with a desired particle size distribution can be obtained. The Al-based foil has a thickness of, for example, at most 0.5 mm, and even 0.1 mm. The Al-based foil is supplied to molten salt in the form of shredded foil pieces. This allows Al-based powder to be obtained with a particle size distribution including fine particles. It is preferred to use, for example, a mixed salt containing NaCl and KCl as molten salt.