eutectic is about 33 by weight copper the near eutectic is about 28 to about 33 copper the infiltrant may be an aluminum based alloy further containing one or more of the following copper magnesium silicon zinc titanium zirconium iron silver lead tin bismuth antimony strontium sodium and nickel in addition to aluminum base alloys aluminum with up to about 53 by weight copper alloy is also acceptable as a non exclusive list the following alloys are useful as the infiltrant all compositions are specified in weight percent each composition may contain other unspecified elements in amount that does not materially affect the infiltration properties described above silicon 8 18 magnesium 3 7 aluminum balance nominal al 13 8 si 4 7 mg melting temperature of 557 u00b0 c copper 28 38 aluminum balance nominal al 33 cu melting temperature of 548 2 u00b0 c silicon 8 12 zinc 8 12 nickel up to 8 aluminum balance silicon 8 12 zinc 8 12 nickel 3 8 aluminum balance nominal al 10 5 si 10 melting temperature of 549 u00b0 c zn 5 5 ni silicon 8 18 aluminum balance nominal al 12 si melting temperature of 577 u00b1 1 u00b0 c once at infiltration temperature generally about 10 u00b0 c above the melting temperature of the infiltrant the part is held at temperature for a time effective for complete infiltration as illustrated in fig1 by numeral 16 of molten infiltrant into the preform on the order of about 1 to about 15 hours and preferably from about 2 hours to about 10 hours at which.