The evolution of manufacture technology of pump bodies turbo-pump assembly LRE

The article describes the methods and tools aimed at improving the quality of body parts turbo-pump assembly (TNA) liquidpropellant rocket engine, which represent parts molded from aluminum-silicon alloy, the outer surface of which is issued by the walls of the mold, and the inner-sand core. One of the problems associated with the casting of aluminum alloys, including aluminum-silicon alloys, is the porosity, the source of which is hydrogen. Pores, formed during crystallization of the metal, weaken the cross-section castings, which reduce their mechanical properties and affect the operational characteristics of TNA. Another defect casting of aluminum alloys is the presence of scattered or concentrated voids, due to the shortage of supply of liquid metal solidified alloy. The activities, aimed at prevention and elimination of the negative influence of the gas-shrinkage defects in case castings TNA, the implementation of which has improved the quality and reduced the number of defective buildings: transferred obtaining castings from casting in the sand form of the in the metallic form; on a sand cores installed "refrigerators", which increased the dissipation heat from the crystallizing metal; working surfaces of the die was covered with a special refractory coating, which ensured the reduction of dissipation and heat transfer in the direction from the lower part to the upper die; developed device for cooling the lower part of the die with compressed air, and heating the upper part of the heaters was established temperature of the die, providing the directional solidification of the casting of the case TNA, are described.