Research On Core Technology For 4FC Aluminum Alloy Engine Clinder

The structure of the sand core using to producing 4FC Aluminum Alloy cylinder is complex and massive.The casting defect such as cold lap,lack of meat,broken core and so on appeared,the surface quality of the casting is bad leading to the high condemning.To avoid these casting defect study of producing non-defect core are carried out.Meanwhile study of quality control and surface coating technology are also carried on.The results show that for the long and thin sand core the shooting sand time is 5S,and the addition volume of triethylamine is 25 ml and purring time is 30 s.For the big plat-like sand core the shooting sand time is 6S;the addition volume of triethylamine is 65 ml and purring time is 30 s.With the same addition volume of resin,while the mixing time increased,sand temperature also rises.when the mixing time increases from 15 seconds to 45 seconds,sand temperature has been increased from 30 to 41 degrees.With the same mixing time,resin content increased from 0.5% to 0.6%,increasion of the sand temperature is not obvious.The temperature of the sand core made by the ordinary sand maintained at 35 degree and tensile strength is kept in the range of 0.9-1.0MPa meeting the strength requirements of process of assembling core box and building up molding box.The temperature of the sand core made by jewelry sand maintained at 38 degree and tensile strength is kept in the range of 0.9-1.0MPa meeting the strength requirements of process of assembling core box and building up molding box.The temperature of the sand core being roasted maintained at 35 degree and tensile strength is kept above 1.0MPa meeting the strength requirements of procession of assembling core box and building up molding box.Compared with the water-proof effect of hydrated magnesium silica,that of 1201 paint,395 paint and the anti-explosion proof water-based paint is obvious better,but the number of reject product causing by bubble increased significantly.The study show that only the explosion proof water-based paint can be using to avoid adhering sand and producing waste productUsing anti-explosion water-based paint whose density of 1.20 g/cm3,avoiding adhering sand,the face quality of casting product and is better than density of 0.8 g/cm3 and 1.0g/cm3.The drying time of sand core is 30±5min in the best drying process and drying temperature is 150 degree.