CN1120066C

CN1120066C - Drum-type apparatus for preparing semi-solid metallic slurry and shaping it

Info

Publication number: CN1120066C
Application number: CN 01109074
Authority: CN
Inventors: 康永林; 安林; 孙建林
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2001-02-28
Filing date: 2001-02-28
Publication date: 2003-09-03
Anticipated expiration: 2021-02-28
Also published as: CN1373020A

Abstract

The present invention relates to a brand-new apparatus for preparing and shaping semi-solid metallic slurry, which is composed of a motor, a bevel gear, a plugging rod, a heat retainer, a heating pipe, a cooling pipe, an internal barrel, an external barrel, a mold cavity, an extrusion cylinder, etc. The internal barrel and the external barrel are designed with an oblique degree alpha of 0 to 10 degrees. The semi-solid metallic slurry enters the slurry chamber of the extrusion cylinder through a one-way valve at the bottom of the barrel; the semi-solid metallic slurry in the extrusion cylinder enters the mold cavity to be quickly pressurized and shaped under the extruding action of a push rod; the extruding speed is from 5 to 100 ms. The present invention has the advantage of simple and compact structure and can realize the continuous forming of the semi-solid slurry from liquid metal and the direct shaping; besides, the metallic slurry has less heat radiation in the whole technological process.

Description

Preparation of drum-type semi-solid metal slurry and former

Technical field

This invention provides a kind of semi-solid metal slurry preparation and former, is mainly used in the preparation and the shaping of semi-solid metal slurry.

Background technology

The semi-solid processing forming technique is to propose early 1970s, is just admitted by people through nearly 30 years its wide application prospect of development.All alloys with solid-liquid two-phase region all can be realized semi-solid processing.This technology has lot of advantages, and for example: carefully and evenly the solidification shrinkage amount is little for tissue, and properties of product, quality obviously improve, and can realize nearly net shape products, have greatly reduced machining amount; With the conventional cast ratio, energy consumption is low; Simultaneously, the semi-solid-state shaping setting time is short, helps boosting productivity etc.The metal that is applicable to semi-solid processing at present has: aluminium alloy, magnesium alloy, cast iron and steel etc., wherein almag has been used for industrial production.But how further the factor that the restriction semi-solid-state metal shapes development is its crystal grain of refinement, the raising structure property, and by liquid state through the semisolid direct forming.Past people energy mainly concentrates on modes such as utilizing electromagnetic agitation, mechanical agitation and carries out the refinement of crystal grain.Promptly strong agitation makes established dendrite fragmentation in the metal cooling procedure, also suppresses the formation of dendrite simultaneously, obtains the avette or near chondritic of non-dendrite.For many years, a large amount of inputs and research have been carried out to Semi-Solid Metals Forming in the home and abroad.In theoretical and application, make remarkable progress.

International semisolid academic conference of in recent years several and data from abroad report, states such as English, the U.S., Japan are all actively developing semisolid preparation and forming technology and equipment and are being used for producing.Beijing: metallurgical industry publishing house; 1999 " semi-solid-state metal process technology and application thereof " books of publishing have been introduced thixotropic forming (Thixomolding) method; be that solid-state Mg-alloy particles or chip are sent into single-screw injection forming machine; effect in heating and sheared helical is issued to semi-molten state formation semisolid, and metal paste is injected casting forming in the die casting at a high speed by nozzle.The semi-solid alloy blank that enters die cavity has only the low-melting body portion of part to be dissolved, and the not fusing of primary phase particulate.In the thixotropic forming process and after being shaped, the primary phase particulate can not experience the process of setting after the heating, and promptly process of setting only is confined on the thick one deck of 5～30 μ m is melted between the primary phase particulate the matrix.This technology many one with a semisolid golden blank chopping operation.The shortcoming that exists is 1, the feed worm operating mode is poor, consumes highly, and the life-span is short; 2 semi-solid alloy mold-filling capacity are poor; 3 equipment needed thereby complexity, the cost height.The double helix semi solid slurry prepares (the UK Patent that forming machine is people such as the Dr Z.Fan invention of Britain Brunel university, Application No 9922696.3,1999), its principle is to utilize double-helical rotation to make liquid metal produce violent turbulent flow, increases the purpose that shear rate reaches the even composition of crystal grain thinning.Double-helical rotation makes its interior metal slurry produce figure of eight motion, and metal paste is travelled forward along screw axial, reaches minimum and maximum detrusion respectively at the engagement place and the root of screw thread.It is suitable for preparation low melting point semi-solid alloy, and obtains certain achievement in the production of Sn-15wt%Pb and Mg-30wt%Zn alloy.But double-spiral structure exists the screw rod operating mode poor equally, consumes height, short problem of life-span.

Summary of the invention

The objective of the invention is to: provide a kind of obtain thin and uniformly semi-solid metal slurry prepare former.

Of the present invention being constructed as follows:

The present invention is by motor 1, bevel gear 2, and stopper 3, warmer 4, heating tube 5,6, cooling tube 7, interior bucket 8, outer bucket 9, check valve 10, push rod 11, semi-solid metal slurry 12, mold cavity 13, squeeze cylinder 14 constitutes.The outside of bucket 9 design outside has heating tube 6 and cooling tube 7, the temperature when realizing controlling the metal paste shear with this.In bucket 8 and 9 designs of outer bucket the gradient of α=0～10 degree is arranged, the slurry chamber that the check valve 10 of semi-solid metal slurry by the bucket bottom enters squeeze cylinder 14.The squeezing action of semi-solid metal slurry in the squeeze cylinder by push rod 11 enters carries out press molding in the mold cavity 13, extrusion speed is 5～100m/s (meter per second).

Overall structure is and is arranged vertically, warmer is fixed in top, by the sprue gate liquid metal is injected slit between the inside and outside bucket, the big I in gap realizes by bucket lifting in regulating, interior bucket is fixed in the rotating shaft, driven by bevel gear by motor, heating tube, cooling tube are equipped with in outer bucket outside, are convenient to the adjusting of metal paste temperature.Squeeze cylinder is in whole device bottom, semi-solid metal slurry can be introduced the slurry chamber of squeeze cylinder by check valve 10, forms the semi-solid processing finished product.

Employing has the inside and outside bucket of gradient, and fixing, the interior bucket of outer bucket is equipped with the slurry chamber that heating tube, cooling tube and bottom have heating and pushing device and constitutes by driven by motor rotation, outer bucket are outside; Be carved with the groove of angle beta=15～75 degree outside on bucket inwall and the interior bucket outer wall, gash depth is 0.001 of an interior bucket external diameter---0.05, the external diameter of interior bucket is 10---200 centimetres, inner and outer barrel wall is thick to be 0.01 of interior bucket external diameter---0.5, highly be 0.5 of interior bucket external diameter---4 times, the gap of inside and outside bucket is 0---3 centimetres, slit and the groove of liquid metal between inside and outside bucket flows downward, when interior bucket rotates, produce very big shear rate between the inside and outside bucket, thereby cause the violent detrusion of liquid metal therebetween, and then form thin and uniform semi-solid metal slurry; Rotatable, the lifting of interior bucket, the big I of shear rate is adjusted slit control for interior barrel by adjusting rotating speed and lifting.

In the actual production, in the warmer 4 that protective atmosphere is arranged, liquid metal is by stopper 3 its downward flows of control.The outside of bucket design outside has heating tube 6 and cooling tube 7, the temperature when realizing controlling the metal paste shear with this.Interior barrel 8 and outer barrel 9 is designed the gradient that has α=0～10 to spend, and the dirty speed that can slow down liquid metal like this has the utilization rate that can improve inside and outside bucket again.In addition, dirty speed of liquid metal and shear rate are controlled in rotating speed and the lifting that can regulate interior bucket.Through after the violent detrusion, the slurry chamber that the check valve 10 of semi-solid metal slurry bottom bucket enters squeeze cylinder.Consider temperature drop, also design the heating tube of control temperature in the squeeze cylinder outside.The squeezing action of semi-solid metal slurry in the squeeze cylinder by push rod 11 enters carries out press molding in the mold cavity 13, extrusion speed is 5～100m/s.

The present invention breaks through traditional crystal grain thinning theory, utilize the detrusion principle, adjust inside and outside bucket slit by bucket in adjustment rotating speed and the lifting, make liquid metals that violent detrusion take place in process of setting, finally can obtain thin and uniform semi-solid metal slurry.This device is different with the principle that external preparation semi-solid metal slurry device forms shear, has also broken through the patent limitation that external thixotropic forming (Thixomolding) and double helix semi solid slurry prepare forming machine (the Twin-Screw Rheomoulder) simultaneously.Realized forming semi solid slurry and direct forming continuously by liquid metal.Overcome the preservation and the bigger restriction of conveying difficulty of the semi solid slurry of rheological method production.The detrusion principle that its novel designs forms when being to utilize traditional mill to rotate, make liquid metal produce big shear rate by inside and outside barrel the reverse rotation of being carved with groove, directly make liquid metal in process of setting, form thin and uniform semi-solid metal slurry efficiently, and simultaneously semi-solid metal slurry is pressed into direct press molding in the mold cavity.Because inside and outside bucket design has α=0～10 degree gradient, so improved its utilization rate, has reduced consumption, has improved the life-span.

Originally the invention has the advantages that: apparatus structure is simply compact, can realize that liquid metal forms semi solid slurry and direct forming continuously.Metal paste dispels the heat few in whole technical process.And be convenient to control, safeguard and use that practicality is extremely strong.

Description of drawings

The present invention is further described below in conjunction with accompanying drawing: Fig. 1 is a kind of schematic diagram of apparatus of the present invention.Wherein motor 1, bevel gear 2, and stopper 3, warmer 4, heating tube 5,6, cooling tube 7, interior bucket 8, outer bucket 9 has heating tube 6 and cooling tube 7, the temperature when realizing controlling the metal paste shear with this in its outside design.In bucket 8 and 9 designs of outer bucket the gradient of α=0～10 degree is arranged, the slurry chamber that the check valve 10 of semi-solid metal slurry by the bucket bottom enters squeeze cylinder 14.The squeezing action of semi-solid metal slurry in the squeeze cylinder by push rod 11 enters carries out rapid press molding in the mold cavity 13, extrusion speed is 5～100m/s.Semi-solid metal slurry 12.

Fig. 2 is the schematic diagram of the outer bucket 9 of the present invention.

Fig. 3 is the schematic diagram of bucket 8 in the present invention.

8A---A is to cutaway view for bucket in the present invention for Fig. 4.

Fig. 5 is the groove schematic diagram of bucket 8 in the present invention.

Claims

1 one kinds of semi-solid metal slurries prepare and former, it is characterized in that: by motor (1), and bevel gear (2), stopper (3), warmer (4), heating tube (5), (6), cooling tube (7), interior bucket (8), outer bucket (9), check valve (10), push rod (11), semi-solid metal slurry (12), mold cavity (13), squeeze cylinder (14) constitutes; The outside of bucket (9) design outside has heating tube (6) and cooling tube (7), the temperature when realizing controlling the metal paste shear with this; The gradient that interior bucket (8) and bucket (9) design outward have α=0～10 to spend, the slurry chamber that the check valve (10) of semi-solid metal slurry bottom bucket enters squeeze cylinder (14); The squeezing action of semi-solid metal slurry in the squeeze cylinder by push rod (11) enters in the mold cavity (13) carries out press molding, and extrusion speed is 5～100 meter per seconds; Overall structure is and is arranged vertically, warmer is fixed in top, by the sprue gate liquid metal is injected slit between the inside and outside bucket, the big I in gap realizes by bucket lifting in regulating, interior bucket is fixed in the rotating shaft, driven by bevel gear by motor, heating tube, cooling tube are equipped with in outer bucket outside, are convenient to the adjusting of metal paste temperature; Squeeze cylinder is in whole device bottom, semi-solid metal slurry can be introduced the slurry chamber of squeeze cylinder by check valve (10), forms the semi-solid processing finished product.

2 semi-solid metal slurry preparation as claimed in claim 1 and formers, it is characterized in that, be carved with the groove of angle beta=15～75 degree outside on bucket inwall and the interior bucket outer wall, gash depth is 0.001 of an interior bucket external diameter---0.05 times, the external diameter of interior bucket is 10---200 centimetres, inner and outer barrel wall is thick to be 0.01 of interior bucket external diameter---0.5 times, highly be 0.5 of interior bucket external diameter---4 times, the gap of inside and outside bucket is 0---3 centimetres, slit and the groove of liquid metal between inside and outside bucket flows downward, when interior bucket rotates, produce very big shear rate between the inside and outside bucket, thereby cause the violent detrusion of liquid metal therebetween, and then form thin and uniform semi-solid metal slurry.

3 as right 1 or 2 described semi-solid metal slurry preparation and formers, be characterised in that, and rotatable, the lifting of interior bucket, the big I of shear rate is adjusted slit control by adjusting the interior bucket of rotating speed and lifting.