Foundry technology of rack of plane of aluminium alloy of high strenth ZL205A

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Plane rack is the important part on the plane, size is larger, the structure is complex, bear dead load and concussion load are bigger, requirement oneself material has high strength, gao Gang is spent, semifinished product casts quality tall, size is exact, in-house organization and function are even and reliable, wait without loose stoma, slag inclusion cast blemish, cast whole is mechanical performance is high. The whole of sand mold of ZL205A of high strenth cast aluminium alloy that uses development of our country proper motion mostly at present casts figuration. The craft of different manufacturer each are not identical, and different technology can create cast constituent allocation, mechanical function the difference that wait. The article sets out from practice, find out craft difficulty, labor and discussed rack foundry technology, do one's best is novel and practical. 1 foundry technology 1.

Alloy of ZL205A of character of 1 alloy foundry technology is AL, Cu fastens high strenth cast aluminium alloy, its chemistry composition sees a table, element of this alloy aggrandizement is much, grain gets refining, different property can be acquired below different heat treatment system, its characteristic is intensity tall, plasticity is good, hardness is tall, machining sex is admirable, finishing sex is good. But Al, the alloy that Cu department alloy is limits of wide crystallization temperature, cast function bad, order of not easy implementation is caky, mural thick sensitivity is great, produce slag inclusion of not close pine, hot tearing, oxidation easily to wait cast blemish, tall to foundry technology requirement, want aggrandizement to stimulate cold, strengthen fill to shrink and take necessary craft step on gating system, create bigger temperature gradient, form better ordinal and caky condition, ability wins compact organization and high grade cast, the high strength that develops ZL205A alloy adequately is characteristic. 1.

Different aircraft plants the structural characteristic of 2 rack and the rack of utility, its dimension and structure have difference, but its appearance and total construction very similar, it is with some plane rack here exemple, if its structure and craft diagram pursue 1, the characteristic is: (1) whole submits compressed form, the structure is complex, over all dimension is big, the clapboard in lumen and muscle many, observe not easily and measure. (2) wall is large evener, heat up a concentration. (3) lumen and window of fluctuation two sides requirement of precision of much, position is strict. (4) hangs a dot to be located in fluctuation two sides, size is large big, performance demand is high. 1.

Analysis of point of 3 foundry technology is shown 1 times by the graph, this cast assembles condition to be vertical. Pull in the plane when rise and descending. Rack can get bigger concussion load, because of this requirement rack each place gets power even, two flank organization is consistent. To achieve this requirement, use vertical pouring the position, can assure cast two flank agree in the composition when crystallization, organization, function, make rack whole function, composition even and reasonable thereby, satisfy use requirement adequately. ZL205A alloy submits congee form caky means.

Must strengthen stimulate cold, ability makes sure the organization is petty and compact with aggrandizement order caky, make each place gets filling goodly shrinking thereby. This cast height is taller, ply is opposite thicker, use the Leng Tie that stick a face half metal type is stimulated cold. Make the ministry is surrounded beyond topping of the surface outside whole cast in cold iron, get adequately when crystallization is caky stimulating cold, rise to refine the organization, function that improves performance thereby. In the meantime, leng Tie the design becomes the form with top thin thick bottom, such but aggrandizement order is caky trend, conduce to caky when the order of from bottom to top fills shrink, make sure cast organization is compact, reduce loose generation. Leng Tiecai uses aluminous refrigeration iron, average ply of Leng Tie takes the Leng Chubi that be stimulated's thick L ~ 1.

2 times, the cold iron ply that concentration heats up a place is added appropriately thick, can increase to 1 of diameter of hot pitch circle.

5 times the left and right sides, be stimulated in order to assure the organization of cold place. Stimulate cold should with fill shrink to close suitably. Ability achieves optimal result, rising head is designed in cast coping, the dimension of rising head is added appropriately substantially tall, take 150 ~ 160mm, fill in order to increase shrink pressure head, sufficient move heats up a section. In order to make sure cast organization is compact, performance is good. Cast structure is complex, size is large, lumen clapboard and muscle many, the window is located in fluctuation two sides more, cast lumen designs integral arenaceous core, the window design that uses fluctuation face transfers core head, will arenaceous core is derivative outside antrum, design big core head to transfer each again core head binds together, in order to assure fixed position and exhaust, use two lateral window to design auxiliary core head, in order to assist fixed position and exhaust. Design integral arenaceous core, be helpful for assuring namely model the structural dimension of antrum is stable, be helpful for increasing the exhaust result of arenaceous core again, make arenaceous core is put at the same time smooth, the operation is simple, be measured easily and adjust. 1.

The design of 4 gating system should be nodded 1.

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The gating system that 1 gating system analyses this cast by straight runner, amortize chamfer, horizontal runner, inside runner, establish canister and the aperture composition that take amortize structure (graph 1) . Among them, amortize chamfer can have the effect of amortize effectively, the generation when preventing the first cold metal to be changed in flow direction splatters and turbulence, those who reduce oxidation be mingled with 2 times generate. Straight runner designs a group a shape runner, can rise effectively to block flows and block broken bits action, horizontal runner designs parallel at two lateral echelon sectional form, make metallic fluid is passed inside runner and aperture runner introduce equably whole model antrum. Rack cast height is taller, sidewall is old plane, can design the runner inside logical aperture pattern to introduce a metal, enter in order to reduce metallic fluid model the perpendicular whereabouts height when antrum, make flow smooth, reduce oxidation slag inclusion 2 times to be in model generate in antrum, reduce the generation that casts blemish thereby. The order that is helpful for from bottom to top at the same time is caky, mix in aperture along with metallic fluid model antrum rises mediumly gradually, reasonable allocation quantity of heat, create good ordinal and caky condition. In addition, the aperture runner that designs on sidewall introduces the rising head, metal fluid in can making establish a canister to be opposite effectively through aperture introduce place to undertake filling shrinking, can raise rising head fill shrink the effect. Reasonable allocation slot gate, assure each aperture span, can make model the metallic fluid flow in antrum is smooth, quantity of heat distributings even and reasonable, reduce the generation with dispersive loose sex. 1.

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Gating system of design of parameter of 2 gating system is the smallest cut face comparing into parts to take 5, cast gross weight (G)200kg, area of the smallest cut is gating system to be taken among them 0.

1, criterion. Straight runner uses every sectional for 0.

8cnl × this N! A group a shape composition, symmetrical distributinging left and right sides two side. Filter the screen pack of pottery and porcelain that uses hole rate to be more than 70 % , put screen pack point is sectional and opposite expand, assure to pass an area. Construction of aperture runner type sees a picture 2, use aperture and stand brief tangent form, establish B of tube of 0 the smallest / with aperture to be D = 4b, b is in mural large size to introduce, a of the wall outside establishing canister center line to be apart from cast takes A = 1.

3D. Aperture bottom adopts a plan the amortize design of 2, can reduce metallic fluid to be opposite model the concussion of core and avoid to produce gas of turbulence, nest and 2 oxidation slag inclusion. Aperture is initiative the left and right sides is in and establish above of brief bottom 40mm at 30mm of cast underside above, transfer with round horn, can prevent cast bottom overheat effectively, create good ordinal and caky condition. 2 conclusion vertical is pouring positional design, can make sure rack whole function, composition is even and reasonable; Half metal mold stimulates type of post face cold iron cold, deserve to fill with reasonable rising head shrink, make sure cast organization is sent, performance is good; Straight runner, horizontal runner and inside runner is sectional than for 1: 3: 5, cooperate to take the reasonable crack of amortize structure, insurable the peace on face of the fluid inside card antrum is firm, reduce cast interior 2 times oxidation be mingled with and interfuse sex gas; Arenaceous core whole is designed, what can assure rack dimension is stable. Through many trial-produce and production, percent of pass can amount to 85% above, explain this foundry technology is reasonable, reliable. CNC Milling