Abstract: A method for cooling a plunger tip of a die-casting machine for maintaining a proper clearance between a plunger tip and a shot sleeve. A proper hydraulic pressure in an injection cylinder is determined at which no galling occurs in the shot sleeve. Hydraulic pressure in the injection cylinder is measured several times in a state where no molten metal exists in the shot sleeve. For example, measured is the hydraulic pressure in the injection cylinder at the time of return stroke of the plunger tip immediately after injecting operation. Average hydraulic pressure is computed based on the plurality of measured hydraulic pressure. The average hydraulic pressure is compared with the proper hydraulic pressure. If the former is greater than the latter, clearance between the plunger tip and the shot sleeve is deemed to be too small. Thus, supply amount of cooling liquid to the plunger tip is increased to reduce a diameter of the plunger tip.

Abstract: A device for detecting galling which may produce deformations during an ejection process of die castings from a die. The device includes a setting device for storing a predetermined set value, the predetermined set value including an upper limit of acceleration of an ejector plate during the ejection process and a predetermined time period during the ejection process. An accelerometer is disposed to the ejector plate for measuring the acceleration thereof during the ejection process. A computing device is provided for comparing the acceleration measured by the accelerometer with the predetermined set value and outputting a warning signal when the acceleration measured at the accelerometer exceeds the upper limit during the time period. Thus, timely detection of galling can result.

Abstract: An aluminum alloy composition represented by the following general formula (I):Al.sub.a Mg.sub.b Ni.sub.c Mn.sub.d Si.sub.e Cu.sub.f Fe.sub.g Ti.sub.h Zn.sub.i B.sub.k Zr.sub.l (I)whereinb=about 2-8 wt %c=0-about 7 wt %d=0-about 3.0 wt %e=0-about 1.0 wt %f=0-about 1.0 wt %g=0-about 0.5 wt %h=0-about 0.3 wt %i=0-about 0.3 wt %j=0-about 0.1 wt %k=0-about 0.1 wt % andl=0-about 0.3 wt %; provided thatc+d.gtoreq.about 0.5 wt %, anda is balance.

Abstract: An alluminum alloy composition represented by the following general formula (I):Al.sub.a Mg.sub.b Ni.sub.c Mn.sub.d Si.sub.e Cu.sub.f Fe.sub.g Ti.sub.h Zn.sub.i B.sub.k Zr.sub.l (I)whereinb=about 2-8 wt %c=0--about 7 wt %d=0--about 3.0 wt %e=0--about 1.0 wt %f=0--about 1.0 wt %g=0--about 0.5 wt %h=0--about 0.3 wt %i=0--about 0.3 wt %j=0--about 0.1 wt %k=0--about 0.1 wt % andl=0--about 0.3 wt %; provided thatc+d.gtoreq.about 0.5 wt %, anda is balance.