Basic Information On Low Melting Point Alloys

The melting point temperature of the low melting point alloy melt material is generally 60 to 200 °C. The melt uses a certain proportion of bismuth, cadmium, tin, lead, dysprosium, indium and other elements as the main components to form different eutectic low melting point alloys.

There are many types of low melting point alloys, and the simpler one used is a bismuth-tin alloy with 58% bismuth and 42% tin. The melting and casting process is as follows: the blended bismuth-tin alloy material is placed in the melting pot, and then heated to about 140 ° C (the temperature can be measured by a semiconductor spot thermometer or a common thermometer), and the mold can be cast after uniform melting. . After casting, it can be cooled for about half an hour. Finally, correct the residual marks left by the casting, that is, to meet the requirements.

For molds with low melting point alloys, the mold temperature should not be too high, and the plastic parts are easy to adhere to the cavity if the mold temperature is too high.

When the inner core of the injection molded part has a large curvature and cannot be manufactured with a steel core (plastic parts with a large curvature, the core cannot be pulled out with ordinary steel), it can be manufactured with a low-melting-point alloy. The manufacturing process is as follows: mix the alloy elements in proportion, pour them into a melting container, heat and melt, and then test the temperature (use ordinary temperature training) to cast the alloy core (the mold for casting the alloy core should be heated to about 60 ℃). ), take out the alloy core after setting.

The core of the above-mentioned low pressure casting is placed in the injection mold, and the injection can be performed. After injection molding, the plastic part is taken out together with the core, and then the alloy core in the plastic part is melted and flowed out by steam heating method (or other heating method), and the plastic part can be obtained.

The low melting point alloy melt material is very sensitive to the change of temperature, so it is suitable for the melt of the temperature type fuse used to protect the electric heating equipment from overheating. For the fuses made with them, the sensitivity of its action should be improved by the mechanical force generated by additional springs, etc. At the same time, the melt itself should also consider the corresponding mechanical strength.