Hydraulic actuator shell and preparation method

A hydraulic actuator shell, comprising a foam metal sandwich composite pipe, a foam metal sandwich flange and a foam metal sandwich end cover, wherein:

• the foam metal sandwich composite pipe is connected with one end of the foam metal sandwich flange, and the foam metal sandwich end cover is connected with the other end of the foam metal sandwich flange;
• the foam metal sandwich flange is in an annular cylindrical structure, the foam metal sandwich end cover is a cylindrical structure, an outer diameter of the foam metal sandwich flange is the same as a diameter of the foam metal sandwich end cover, a plurality of first through holes are uniformly arranged on a toroidal surface of the foam metal sandwich flange along a circumferential direction, and a plurality of second through holes in one-to-one correspondence with the first through holes are arranged on a circular surface of the foam metal sandwich end cover;
• the foam metal sandwich end cover and the foam metal sandwich flange are cut by a foam metal sandwich composite plate, the foam metal sandwich composite plate sequentially comprises a first corrugated metal layer, a second foam metal layer and a second corrugated metal layer from top to bottom, a bonding interface among the first corrugated metal layer, the second corrugated metal layer and the second foam metal layer is a second metallurgical bonding interface, and the second bonding interface is a corrugated interface;
• the foam metal sandwich composite pipe comprises a first metal pipe layer, a first foam metal layer and a second metal pipe layer sequentially arranged from inside to outside;
• and a first bonding interface among the first metal pipe layer, the first foam metal layer and the second metal pipe layer is a metallurgical bonding interface;
• the foam metal composite pipe is obtained by placing a target composite pipe blank in a heating furnace and foaming a middle layer of the target composite pipe blank to form the first foam metal layer;
• the target composite pipe is obtained by putting a composite pipe blank into a first annular cavity formed by an extrusion inner mold and an extrusion outer mold, fixing the extrusion outer mold by an extruder, starting a first induction heating coil arranged in the extrusion inner mold to heat the first metal pipe layer to a first target temperature, starting a second induction heating coil arranged in the extrusion outer mold to heat the second metal pipe layer to a second target temperature, and pushing one end of the extrusion inner mold by a extrusion head to move along an axial direction of the composite pipe blank, so that the composite pipe blank is extruded from an extrusion end of the first annular cavity and formed, and a temperature of a first contact interface is raised to a preset temperature during extrusion, and the first contact interface is re-melt to form the first metallurgical bonding interface;
• wherein, the preset temperature is greater than or equal to a melting point temperature of an annular pre-fabricated foam blank, a target temperature comprises the first target temperature and the second target temperature, and the first target temperature and the second target temperature are both smaller than the melting point temperature;
• the composite pipe blank comprises a first metal pipe layer, an annular prefabricated foam blank and a second metal pipe layer from inside to outside;
• and
• the foam metal sandwich composite pipe is prepared by an extrusion tool, and the extrusion tool comprises:
• the extrusion inner mold, wherein the extrusion inner mold comprises an inner mold cylinder with a T-shaped structure, the inner mold cylinder comprises a head part and a tailing part, the tailing part is provided with a cylinder cavity;
• the first induction heating coil is arranged in the cylinder cavity, an inner mold insulating pad is arranged between the first induction heating coil and the cylinder cavity, an inner mold end cover is arranged at one end of the cylinder cavity far from the head part, the inner mold end cover is connected with the inner mold cylinder through an inner mold fastening screw, and the inner mold end cover is used for forming an enclosed space in the cylinder cavity;
• the extrusion outer mold, wherein the second induction heating coil is arranged in the extrusion outer mold, an inner wall of the extrusion outer mold comprises a large-diameter section, a slope section and a small-diameter section, the large-diameter section and the small-diameter section are in transition connection through the slope section, the large-diameter section of the extrusion outer mold is matched and sleeved with the head part of the inner mold cylinder, the first annular cavity is formed between the inner wall of the extrusion outer mold and a tailing part of the extrusion inner mold, and one end of the first annular cavity close to the small-diameter section is an extrusion end;
• the extruder, used for clamping and fixing an outer wall of the extrusion outer mold;
• and
• the extrusion head, used for pushing the extrusion inner mold to make the composite pipe blank move along the axial direction and be extruded from the extrusion end of the first annular cavity.