CN103128229A

CN103128229A - Investment casting mold cavity cleaning method based on selected area laser powder sintering rapid proto-typing technology application

Info

Publication number: CN103128229A
Application number: CN2011103931158A
Authority: CN
Inventors: 文明; 蓝勇
Original assignee: DONGFENG INVESTMENT CASTING Co Ltd
Current assignee: DONGFENG INVESTMENT CASTING Co Ltd
Priority date: 2011-11-26
Filing date: 2011-11-26
Publication date: 2013-06-05

Abstract

Disclosed is an investment casting mold cavity cleaning method based on selected area laser powder sintering rapid proto-typing technology application. According to the technical scheme, the top end of a wax mold and the secondary top end of the wax mold are connected with a residue discharging channel and a residue collecting device in a welded mode in a mold set assembling process. After a shell manufacturing process and a dewaxing process, flowing discharging of a wax mold in a liquid state and gathering of remained residues can be effectively controlled in a baking process, so that a clean mold cavity is obtained. After a series of well-known investment casting technology such as smelting, pouring, sand cleaning and piece dropping, an investment casting with a surface and an interior being good in quality is obtained.

Description

A kind of model casting die cavity clean method of using based on the powder sintered rapid shaping technique of precinct laser

Affiliated technical field

The present invention relates to the application of the powder sintered rapid shaping technique of precinct laser in model casting, it provides a kind of die cavity clean method, is used for improving inherence and the surface quality of investment-casting.

Background technology

The powder sintered rapid shaping technique of precinct laser (hereinafter to be referred as the SLS technology) is one of rapid shaping technique method, is also one of rapid shaping technique method of using as far back as the model casting field.

the agglomerated material that the SLS technology is used is high molecular composite powder, the prototype of being fired by forming machine, through post processing, become wax-pattern and (or claim part, lower same), but the wax material of this wax-pattern and the actual use of traditional model casting is different, show as fusing point high (approximately 180 ℃), can not being melted (or vaporization) in the dewaxing operation sloughs, must fall in the calcining process ablation, experiment shows: the module roasting is a very complicated physicochemical change process, comprise that wax-pattern fusing flows out along running channel, gasification is decomposed, the remaining residue of partially carbonized formation is stranded in die cavity.

Engineering test shows, impact is fatal to remaining residue on casting quality.In the SLS technology was used initial stage and longer a period of time, generally after the module bakes to burn the article, take several different methods cleaning die cavity: 1. warm water cleaned; 2. organic solvent (as alcohol etc.) cleans; 3. air-flow blows down remaining residue; 4. above several method is used in combination etc.; Carry out again afterwards after baking, and higher to the roasting requirement for environmental conditions.

The module anatomy experiment shows: even if the laggard row after baking of cleaning die cavity, remaining residue still is difficult to complete ablation totally, through incomplete experiment of weighing statistics, its remaining residue content reaches 0.25～0.5% (mass fraction), cast when filling type molten steel (or molten metal) can wash away these remaining residues and it is involved in molten metal, thereby make foundry goods pore occur, be mingled with and the casting flaw such as local shape is imperfect.

The die cavity of cleaning is one of important prerequisite condition that guarantees foundry goods inherence and surface quality, above-mentioned casting flaw has not only affected casting quality, also making the application of SLS technology in model casting produce some is not suitable with and perplexs [referring to " model casting handbook, the 20th chapter, computer technology is used in model casting, and the 560th page, China Association of Casting compiles, China Machine Press, version in 2006].

Summary of the invention

Generally, after the location positioning of wax-pattern in module, it has 1 top (being peak) and a plurality of tops (i.e. time high point); And when standing upside down (be cup down) at module, its 1 top and a plurality of tops just are converted to 1 least significant end (being minimum point) or a plurality of low sides (i.e. inferior low spot).The module anatomy experiment shows, after module (handstand) roasting, the remaining residue of wax-pattern always is gathered in least significant end and time low side position of wax-pattern die cavity.

Based on above analysis and the fact, the die cavity cleaning problems that exists in investment casting applications for solving the SLS technology the invention provides a kind of clean method, and its technical scheme is:

1, during module group assembling, between the top (or a plurality of tops) of wax-pattern and module sprue (or cup), drainage channel is set, when being convenient to module (handstand) roasting with liquid wax-pattern drainage to running gate system, be called dreg discharging tunnel;

2, during module group assembling, on the top (or a plurality of tops) of wax-pattern, a kind of container is set, when being convenient to module (handstand) roasting, the remaining residue of wax-pattern is gathered in this container, is called dirt trap;

The method that dreg discharging tunnel and dirt trap more than are set may be used alone, can also be used in combination, and should look concrete condition and grasp flexibly.

The invention has the beneficial effects as follows, the mobile eliminating of liquid wax-pattern and the gathering of remaining residue when effectively controlling module (handstand) roasting, shell die cavity cleannes have been improved, and then foundry goods inherence and surface quality are guaranteed, operation is implemented simple, module adapts to various roasting environment (resistance furnace, oil burner, car type furnace, rotary furnace, continuous passing-type furnace etc.), need not manual intervention cleaning die cavity and after baking.

Description of drawings

Below in conjunction with drawings and Examples, the inventive method is described further.

Fig. 1 is the wax-pattern stereogram by the SLS fabrication techniques.

In figure, 1. wax-pattern; 2. ingate.

Fig. 2 is technical solution of the present invention enforcement figure.

In figure, 1. dreg discharging tunnel; 2. dirt trap; 3. dirt trap; 4. wax-pattern; 5. ingate; 6. sprue; 7. cup; 8. suspending apparatus; 9. top; 10. top; 11. inferior top.

The specific embodiment

In Fig. 2, during the module group assembling operation, wax-pattern (4) position in module determined, cup (7) rim of a cup is up the time, and wax-pattern (4) has top (9), top (10) and time top (11).

1, the concrete grammar of welding dreg discharging tunnel is:

In Fig. 2, weld dreg discharging tunnel (1) between the top (9) of wax-pattern (4) and cup (7) and sprue (6), the diameter of section size of dreg discharging tunnel (1) is about 1/3～3/4 of wax-pattern (4) top wall thickness, length to be forming and sprue (6) and cup (7) axis angle approximately at 45 °, and the drainage eliminating of liquid wax-pattern (4) is advisable when being conducive to calcining process.

2, the concrete grammar of welding dirt trap is:

In Fig. 2, top (10) and time top (11) welding dirt trap (2) (3) in wax-pattern (4), cross section (diameter) size of dirt trap (2) (3) is about approximately 1/3～3/4 of wax-pattern (4) top (10), inferior top (11) wall thickness, and extension elongation is that 1/2～2 times of wall thickness is advisable.

The method of above welding dreg discharging tunnel and dirt trap may be used alone, can also be used in combination, and should look concrete condition and grasp flexibly; The material of welding dreg discharging tunnel and dirt trap can be selected small-sized shaft-like material that operation field made by traditional wax material and block material etc. on the spot.Module group assembling enters subsequent handling after finishing.

In Fig. 2, running gate system comprises sprue (6) and cup (7), is made by traditional wax material, through shell operation processed, only sloughs the running gate system wax material during dewaxing operation; Calcining process is also slightly different from traditional handicraft, and during roasting, module must stand upside down, and namely cup (7) rim of a cup, is positioned over suspending apparatus (8) down, and general smallclothes are by traditional handicraft 1.5 stove time roastings, and large part is by 2～3 stove time roastings.

Claims

1. model casting die cavity clean method of using based on the powder sintered rapid shaping technique of precinct laser, its technical characterictic is:

(1) during the module group assembling operation, weld dreg discharging tunnel between the top of wax-pattern and sprue and cup.

(2) during the module group assembling operation, at top and time top welding dirt trap of wax-pattern.

(3) during the module group assembling operation, at top and time top Combination Welding dreg discharging tunnel and the dirt trap of wax-pattern.