6results about How to "Avoid heat cracks" patented technology

The application belongs to the technical field of laser additive manufacturing, and particularly relates to an array type laser additive manufacturing method and device, which comprises the following steps: S1, digital model import and layering slicing; S2, scanning path planning and filling setting; S3, array type laser synchronous output control; S4, powder flow and powder feeding path control; S5, according to the width of the additive, the width of single track cladding is adjusted in real time; S6, according to the slice layer material of the additive, the matching material is delivered; S7, S1-S6 are repeated, and layer-by-layer accumulation is performed until the part manufacturing is completed. The application can accurately control the grain size, improve the material microstructure, and improve the mechanical properties; the generation of defects such as thermal cracks and pores is reduced, the stability of the deposition process is ensured; the interlayer bonding is optimized, the quality of multi-layer deposition is ensured; the residual stress is reduced, the size precision, shape stability and fatigue performance of the part are improved; the post-processing requirement is reduced, and the processing cost is reduced.

The application discloses a multi-furnace body series connection step-by-step continuous heating furnace, and relates to the technical field of heating furnaces.The heating furnace comprises a furnace loading base, a preheating base is fixedly installed at the rear bottom end of the furnace loading base through bolts, a heating base is fixedly installed at the rear side of the preheating base through bolts, and a furnace loading structure is arranged.The furnace loading structure comprises two fixed support rails which are fixedly installed at the top end of the furnace loading base through bolts.The application is provided with a plurality of furnace bodies, the preheating furnace body is separated from the heating furnace body, the high-temperature flue gas of the heating furnace body is used as the heat source of the preheating furnace body to preheat the steel billet, the flue gas temperature discharged from the preheating furnace body is the final flue gas temperature of the heating furnace body, a small amount of burners can be arranged in the preheating furnace body as auxiliary heating and adjusting burners, the flue gas temperature of the heating furnace can be accurately controlled, the flue gas temperature can be controlled at the lower limit of the anti-dew-point corrosion temperature, the energy consumption is reduced, and the chimney is not corroded.

The application discloses a kind of vacuum electron beam welding methods of beryllium aluminum alloy, belong to metal material welding technical field, comprising the following steps: A, beryllium aluminum alloy plate is polished and cleaned and is handled;B, beryllium aluminum alloy plate is clamped with welding fixture, and the position to be welded is placed in the welding work area of electron beam welding system workstation;C, electron beam welding system is pumped to welding work vacuum degree, sets welding process parameter;D, preheating treatment is carried out to workpiece before welding, starts electron beam welding system, and beryllium aluminum alloy plate is welded;E, after welding, carries out postwelding slow cooling treatment.The application is designed by electron beam welding process and tooling fixture, optimizes electron beam welding heat input, controls cooling rate and the like mode, improves the uniformity of weld molten metal composition and organization, and the beryllium aluminum alloy weld obtained is not only free from crack, pore and other welding defects, simultaneously, but also makes the mechanical property of welded joint better than base material.

The invention discloses a contractible composite core for metal casting, which is characterized in that a plurality of movable core blocks form an annular core, and end gaps and end gap liquid blocking devices are arranged among the movable cores to prevent casting liquid from flowing out of the end gaps; the bottom of each core block is a plane and is placed on the plane of the lower die or is respectively arranged on different rolling or static pressure guide rails, a gap between each core block and the bottom of the lower die is smaller than an overflow edge value or is filled with a refractory material, and each core block can freely move inwards along with the shrinkage of a casting in a solidification shrinkage stage after casting liquid is poured; and hot cracks caused by the obstruction of the mold core can be prevented.

The utility model discloses a heat crack resistant casting reinforcing rib structure of an automobile brake disc, which is arranged on an inner side friction plate close to a wheel and positioned in a space between an outer side friction plate and the inner side friction plate, and comprises a plurality of radial reinforcing ribs, an outer ring reinforcing rib and an inner ring reinforcing rib, each radial reinforcing rib is arranged in an S shape, the outer ring reinforcing ribs are annularly arranged on the outer ring of the inner side friction plate in the circumferential direction of the inner side friction plate, and the inner ring reinforcing ribs are annularly arranged on the inner ring of the inner side friction plate in the circumferential direction of the inner side friction plate. According to the brake disc, the radial reinforcing ribs, the outer ring reinforcing ribs and the inner ring reinforcing ribs are matched with one another to form a complete reinforcing structure system and act together in different directions, so that the brake disc can bear complex stress conditions, the overall mechanical property is improved, and the brake disc better meets the requirements under various brake conditions; and safe and reliable operation of an automobile brake system is ensured.

This invention relates to the field of casting technology and discloses a casting process for marine engine blades, comprising: preparing three types of molding sand with different compositions: surface molding sand, intermediate molding sand, and back molding sand; sequentially filling the surface of the pattern with surface molding sand, intermediate molding sand, and back molding sand using a layered compact molding method to form a gradient structure mold; introducing CO2 gas to harden the mold; applying a silica sol coating to the surface of the mold cavity; drying the surface to form a siliceous glassy film from the silica sol; pouring molten metal into the mold after closing the mold, and pouring at high temperature to decompose the organic pore-forming agent in the back molding sand to create pores in situ; and demolding after solidification and cooling to obtain the casting. This invention, through its gradient layered structure and surface sealing treatment, reduces the mold expansion rate while establishing a permeability gradient from the surface to the back layer, preventing molten metal penetration and promoting gas expulsion, effectively solving the problems of hot cracking, porosity defects, and surface sand adhesion in the casting of marine engine blades.