Reduce the preparation method and its fusible pattern system of titanium investment precision casting surface roughness
Preparation Method
Technical field
The invention belongs to melted module precise casting technology field, it is related to casting a kind of low surface roughness titanium investment precision
The improvement of the preparation method of part and its fusible pattern.
Background technique
Titanium alloy precision casting mainly uses precision-investment casting method to prepare, and prepares fusible pattern using fusible material, then
On fusible pattern surface, shell is made in cladding several layers refractory material, by the Baking after removing fusible pattern, obtains stable shell, so
Casting pouring is carried out using shell afterwards.At present using precision-investment casting method preparation titanium alloy casting surface roughness between
3.2 between~6.3 μm.Surface roughness, size since titanium alloy casting is primarily used to aerospace field, to casting
Precision and use reliability have higher requirement, the surface roughness and the fiting property of product, wearability, fatigue of medium casting
Intensity, contact stiffness, vibration and noise etc. have close relationship, and the service life and reliability to product have important influence,
Thus require titanium alloy casting surface roughness will be lower than 3.2 μm hereinafter, key area requirement to crucial casting or casting
Surface roughness even requirement is lower, and conventional precision-investment casting method is used to cannot achieve.
Since first process of precision-investment casting is exactly to manufacture fusible pattern, to obtain surface smoothness and dimensional accuracy is high
Casting, fusible pattern first answers surface smoothness and dimensional accuracy with higher.Secondly, casting be using shell casting preparation and
At, thus the surface smoothness of investment shell intracavity also influences the surface roughness of casting.After shaping due to casting, inside can not be kept away
Exempt from there can be metallurgical imperfection, need to eliminate by the method for Welding Repair, also have large effect to cast(ing) surface, thus needs
Reduce the one-time formed ratio of defects of casting.Since precision-investment casting process is long, each process all has an impact to surface roughness,
The process surface roughness control for carrying out concerned process steps, is just able to achieve surface roughness reduction.It is simultaneously further drop
Low surface roughness need to carry out specially treated to cast(ing) surface, and in conjunction with kinds of processes effect, it is thick to reduce cast(ing) surface step by step
Rugosity realizes surface roughness lower than 2 μm or less.
Summary of the invention
The purpose of the present invention is overcoming the above-mentioned prior art, a kind of low surface roughness titanium investment essence is provided
The preparation method of close casting and its fusible pattern.
The technical scheme is that reducing the preparation method and its fusible pattern of titanium investment precision casting surface roughness
Preparation method, preparation of the preparation method for the titanium investment precision casting and its fusible pattern of low surface roughness, wherein
Fusible pattern preparation step comprising casting, fusible pattern preparation carry out in the steps below:
The preparation simulation of 1.1 fusible patterns, includes following step:
1.1.1 according to the threedimensional model of casting, fusible pattern model and mold former are designed;
1.1.2 surface grids and volume mesh is carried out using numerical simulation software dividing, formed can be used for simulating with grid
Side length≤5mm of fusible pattern model and mold former, the surface grids and volume mesh;
1.1.3 fusible pattern simulating boundary parameter is set;
1.1.4 fusible pattern preparation technology parameter is set, wherein mold preheating temperature parameter is between 25~50 DEG C, fusible pattern note
Temperature is penetrated between 55~85 DEG C, fusible pattern injection pressure between 0.5~2MPa, the fusible pattern dwell time between 150s~
Between 500s, under the conditions of evaluating different parameters, fusible pattern surface flow marks quantity and size, and carry out process parameter optimizing;
1.1.5 it according to the analog result of step 1.1.4, observes in fusible pattern cavity filling process, the flowing side of fusible pattern in a mold
To with fill type sequence, pass through change mold injection port design position, come change the flowing of fusible pattern and fill type sequence, reduce fusible pattern
Turbulent flow steadily sequentially fills type, determine mold injection port design position and final die design schemes;
1.1.6 on the basis of the design scheme of the step 1.1.5 mold determined, repeat step 1.1.4, according to step
The analog result prediction fusible pattern defect of rapid 1.1.4 generates position, will by adjusting the fusible pattern preparation technology parameter of step 1.1.4
Ratio of defects reduces by 10% or more.
1.2 prepare fusible pattern, according to investment pattern die and fusible pattern preparation technology parameter that step 1.1 is formulated, prepare fusible pattern.
It is described reduce titanium investment precision casting surface roughness preparation method and its fusible pattern preparation method, further include
Fusible pattern reparation, for fusible pattern, there are the positions of surface defect to carry out local route repair.
The fusible pattern reparation includes following step:
The 3.1 position equatings that need to repair fusible pattern;
3.2 repair position with sand paper polishing fusible pattern, and when polishing carries out according to the granularity point three-level of sand paper, using different model
Sand paper polished step by step fusible pattern surface reconditioning area, it is thin after first thick;
3.3 cleaning fusible patterns.
In step 3.1, the region that fusible pattern surface need to be repaired repairs mould material using brushing or repeatedly drippage repairs mould material
Mode repaired, being repaired fusible pattern depression in the surface region, mould material fills up or the elevated regions on fusible pattern surface are micro- molten
Change, the region equating that then need to repair on the fusible pattern surface.
In step 3.2, fusible pattern repairs sand paper model used are as follows: the first order sand paper model mesh of 500≤M1 < 800, second level sand
The mesh of 800≤M2 of paper mold number < 1200, the third level sand paper model mesh of 1200≤M3 < 2000.
The specific steps of step 3.3 fusible pattern cleaning are as follows: first impregnated using clear water, then impregnated with organic reagent, finally used
Clear water rinses.
Clear water, which impregnates, uses ultrasonic vibration mode.
A kind of preparation method reducing Melt casting surface roughness, the specific steps of which are as follows:
The preparation of 8.1 fusible patterns, fusible pattern preparation step carries out according to claim 1;
The design of 8.2 casting moulding systems carries out sunykatuib analysis to Filling Processes of Castings process of setting using the method for numerical simulation,
The running gate system of designing cast;
Prepared by the fusible pattern of 8.3 Strip casting systems, according to the running gate system scheme of Numeric simulation design in step 8.2, complete
Fusible pattern and running gate system combination;The fusible pattern surface defect reparation that identical mode carries out Strip casting system is repaired using with fusible pattern;
The preparation of 8.4 shells carries out shell preparation using the fusible pattern of Strip casting system;
8.5 casting pourings, preheat shell, then carry out casting pouring, prepare casting;
8.6 blasts carry out the processing of surface blast to the casting after removal running gate system;Using the sand of 30~80 mesh;
8.7 pickling carry out process processing to the casting after a blast, then carry out surface acid-washing, and casting is thick after pickling
Removal amount a≤5mm of degree;
8.8 2 blasts carry out the processing of surface blast to the casting after pickling;Using the sand of 80~250 mesh, several times,
Multi-level blast from thick to thin.
In the design of step 8.2 casting moulding system, Filling Processes of Castings process of setting is simulated using numerical simulation software, and to casting
Part defect is predicted that ratio of defects of the running gate system of design Jing Guo numerical Simulation Prediction need to be lower than 8%.
In step 8.5 casting pouring, the preheating temperature of shell is 100~500 DEG C before casting pouring, keeps the temperature 2~8 hours.
In step 8.5 casting pouring, casting pouring 20~50KA of electric current, casting 50~100V of voltage, melting vacuum degree≤
7.0Pa, casting cooling time >=2 hour.
In step 8.7 pickling, pickling solution HNO3The mixed solution of+HF+ additive.
In two blasts of step 8.8, three-level granularity is divided to carry out blast, it is primary that every grade of granularity at least carries out blast;Wherein
Primary particle size is the mesh of 80≤N1 < 120, and second level granularity is the mesh of 120≤N2 < 200, and third level granularity is the mesh of 200≤N3 < 250;Often
After grade granularity blast, surface roughness are detected according to surface roughness value and qualification rate and judge the granularity of next stage,
Until surface roughness meet the requirements.
Region after cast(ing) surface blast is detected, taking a position includes the outside, middle part and inside in blast region,
It takes quantity a little to be determined according to blast area size, takes at random a little;The surface roughness value of a position is taken to meet current level
When the corresponding surface roughness value of granularity, for qualification, statistics takes the qualification rate of a position, can be into when qualification rate >=70%
The other granularity of row next stage;
When the surface roughness value for taking a position of statistics meets the corresponding surface roughness value of next stage granularity simultaneously
And when qualification rate >=70%, leapfrog blast can be carried out, until surface roughness reaches requirement.
The mesh blast rear surface of 80≤N1 < 120 roughness Ra≤3 μm, the mesh blast rear surface of 120≤N2 < 200 roughness Ra≤
2.5 μm, the mesh blast rear surface of 200≤N3 < 250 roughness Ra≤2 μm.
The invention has the following advantages:
The preparation method of titanium investment precision casting provided by the invention, reduces the table of titanium alloy casting and its fusible pattern
Surface roughness, the surface roughness of conventional titanium investment precision casting is between 3.2 μm~6.3 μm, and the method for the present invention
Surface roughness Ra≤2 μm of the titanium investment precision casting of preparation, and casting defect rate reduces by 30% or more, mentions significantly
The high quality and use reliability of titanium alloy precision casting.
Specific embodiment
The present invention is described in further details below.
A kind of preparation method and its fusible pattern preparation method reducing titanium investment precision casting surface roughness, this method
Include the following steps: the fusible pattern of fusible pattern preparation simulation, fusible pattern preparation, fusible pattern reparation, casting moulding system design, Strip casting system
Preparation, shell preparation, casting pouring, a blast, pickling, secondary blast.The preparation method is as follows:
The preparation of 1 fusible pattern
The preparation simulation of 1.1 fusible patterns, includes following step:
1.1.1 according to the threedimensional model of casting, fusible pattern threedimensional model and mold threedimensional model are designed;
1.1.2 surface grids and volume mesh is carried out using numerical simulation software dividing, formed can be used for simulating with grid
The selection required precision of side length≤5mm of fusible pattern model and mold former, the surface grids and volume mesh, the side length can be protected
Hinder fusible pattern model accuracy, with the requirement of ultimate guarantee fusible pattern surface roughness;
1.1.3 fusible pattern simulating boundary parameter is set;
1.1.4 fusible pattern preparation technology parameter is set, under the conditions of evaluating different parameters, the quantity and ruler of fusible pattern surface flow marks
It is very little.Wherein mold preheating temperature parameter is between 25~50 DEG C, and fusible pattern injection temperature is between 55~85 DEG C, fusible pattern injection
Pressure between 0.5~2MPa, the fusible pattern dwell time between 150s~500s, with less surface flow marks;
1.1.5 it according to the analog result of step 1.1.4, observes in fusible pattern cavity filling process, the flowing side of fusible pattern in a mold
To with fill type sequence, pass through change mold injection port design position, come change the flowing of fusible pattern and fill type sequence, reduce fusible pattern
Turbulent flow steadily sequentially fills type, and formulates the design position of mold injection port and the design scheme of mold;The design side of investment pattern die
Case is mainly the structure according to fusible pattern, but the selection of fusible pattern injection port has large effect to the flowing of fusible pattern in a mold,
It is turbulent easily to form volume gas and surface defect, thus type is filled by simulated implementation fusible pattern sequence, advantageously reduce fusible pattern surface and interior
Portion's defect reduces fusible pattern surface reconditioning, improves fusible pattern surface smoothness;
1.1.6 on the basis of the design scheme of the step 1.1.5 mold determined, repeat step 1.1.4, according to step
The analog result prediction fusible pattern defect of rapid 1.1.4 generates position, will by adjusting the fusible pattern preparation technology parameter of step 1.1.4
Ratio of defects reduces by 10% or more.By reducing fusible pattern ratio of defects, the destruction to the reparation of fusible pattern and to fusible pattern surface is reduced.
1.2 prepare fusible pattern, according to investment pattern die and fusible pattern preparation technology parameter that step 1.1 is formulated, prepare fusible pattern;
1.3 fusible pattern reparations, for fusible pattern, there are the positions of surface defect to carry out local route repair, includes the following steps:
1.3.1 the position equating that fusible pattern need to be repaired;
The region that fusible pattern surface need to be repaired is carried out by the way of brushing reparation mould material or repeatedly drippage reparation mould material
It repairs, so that fusible pattern depression in the surface region is repaired mould material and fill up or the micro- fusing of the elevated regions on fusible pattern surface, then should
The region equating that fusible pattern surface need to repair.
The size in the region that fusible pattern surface need to repair is with the outermost side profile of surface indentation region or surface raised areas
Basis, extend outwardly certain size, and the size of heat affected area is repaired by control fusible pattern, avoids restoring area too small, after reparation
Can exist and repair surface local dent, or reparation area is excessive, the heat affected area for repairing surface is excessive, influences fusible pattern surface matter
Amount;
1.3.2 position is repaired with sand paper polishing fusible pattern, when polishing carries out according to the granularity point three-level of sand paper, using different shaped
Number sand paper polished step by step fusible pattern surface reconditioning area, it is thin after first thick, fusible pattern repairing effect has been effectively ensured.
Fusible pattern repairs sand paper model used are as follows: the first order sand paper model mesh of 500≤M1 < 800, second level sand paper model 800
The mesh of≤M2 < 1200, the third level sand paper model mesh of 1200≤M3 < 2000.Fusible pattern surface strength is low, and thicker sand paper cannot not only reach
To the effect on polishing fusible pattern surface, fusible pattern surface can be scratched instead, improve fusible pattern surface roughness.By repairing sand paper to fusible pattern
The specific of granularity selects and designs step by step, can be with effective guarantee fusible pattern repairing quality and remediation efficiency.
1.3.3 fusible pattern is cleaned.
The specific steps of fusible pattern cleaning are as follows: first impregnated using clear water, then impregnated with organic reagent, finally rushed with clear water
It washes.Clear water, which impregnates, uses ultrasonic vibration mode.
2, a kind of preparation method for reducing titanium investment precision casting surface roughness as described in claim 1, it is special
Sign is, the specific steps are as follows:
The preparation of 2.1 fusible patterns, fusible pattern preparation step carries out according to claim 1;
The design of 2.2 casting moulding systems carries out sunykatuib analysis to Filling Processes of Castings process of setting using the method for numerical simulation,
The running gate system of designing cast;
Casting defect prediction is carried out using the casting moulding system design of design, the running gate system of design passes through numerical simulation
The ratio of defects of prediction need to be lower than 8%.
Prepared by the fusible pattern of 2.3 Strip casting systems, according to the running gate system scheme of Numeric simulation design in step 2.2, complete
Fusible pattern and running gate system combination;The fusible pattern surface defect reparation that identical mode carries out Strip casting system is repaired using with fusible pattern;
The preparation of 2.4 shells carries out shell preparation using the fusible pattern of Strip casting system;
2.5 casting pourings, preheat shell, then carry out casting pouring, prepare casting;
The preheating temperature of shell is 100~500 DEG C before casting pouring, keeps the temperature 2~8 hours.
Casting pouring 20~50KA of electric current is poured 50~100V of voltage, melting vacuum degree≤7.0Pa, casting cooling time
>=2 hours.The combination of above-mentioned parameter selects and control, is conducive to the control of cast(ing) surface oxidated layer thickness, to improve casting
Surface smoothness.
2.6 blasts carry out the processing of surface blast to the casting after removal running gate system;Using the sand of 30~80 mesh;
So as to effective guarantee blast efficiency and effect, while surface being avoided blast damage occur.The granularity selection of blast with
The oxide layer that titanium alloy casting surface is formed after investment pattern precision casting is related, and surface oxide layer belongs to brittle layer, is easily formed on surface micro-
Cracks influence surface roughness and surface quality can go most of oxide layer by a blast, be conducive to rear process into one
Step removal and control.
2.7 pickling carry out process processing to the casting after a blast, then carry out surface acid-washing, and casting is thick after pickling
Removal amount a≤5mm of degree;
Pickling solution is HNO3The mixed solution of+HF+ additive.
2.8 2 blasts carry out the processing of surface blast to the casting after pickling;Using the sand of 80~250 mesh, several times,
Multi-level blast from thick to thin.
Secondary blast divides three-level granularity to carry out blast, and it is primary that every grade of granularity at least carries out blast;Wherein first order granularity is
The mesh of 80≤N1 < 120, second level granularity are the mesh of 120≤N2 < 200, and third level granularity is the mesh of 200≤N3 < 250;Every grade of granularity blast
Afterwards, detection surface roughness judge the granularity of next stage according to surface roughness value and qualification rate, until casting table
Surface roughness meets the requirements, and during blast, sand fineness is chosen improper, and it is unfavorable to generate to surface quality of continuous castings
It influences.
Region after cast(ing) surface blast is detected, taking a position includes the outside, middle part and inside in blast region,
It takes quantity a little to be determined according to blast area size, takes at random a little;The surface roughness value of a position is taken to meet current level
When the corresponding surface roughness value of granularity, for qualification, statistics takes the qualification rate of a position, can be into when qualification rate >=70%
The other granularity of row next stage;
When the surface roughness value for taking a position of statistics meets the corresponding surface roughness value of next stage granularity simultaneously
And when qualification rate >=70%, leapfrog blast can be carried out, until surface roughness reaches requirement.
The mesh blast rear surface of 80≤N1 < 120 roughness Ra≤3 μm, the mesh blast rear surface of 120≤N2 < 200 roughness Ra≤
2.5 μm, the mesh blast rear surface of 200≤N3 < 250 roughness Ra≤2 μm.Secondary blast is controlled by the blast granularity of different stage
It is detected with surface roughness, on the basis of removing titanium alloy casting surface brittleness oxide layer, further increases surface smoothness.
Embodiment one
A kind of frame shape titanium investment precision casting, casting dimension are 900 × 310 × 460mm.The overall surface of casting is thick
Rugosity requires to be less than Ra≤2 μm.This method includes the following steps: that fusible pattern preparation simulation, fusible pattern preparation, fusible pattern reparation, casting pour
Fusible pattern preparation, shell preparation, casting pouring, a blast, pickling and the secondary blast of injection system design, Strip casting system.System
Preparation Method is as follows:
The preparation of step 1 wax-pattern
The preparation simulation of 1.1 wax-patterns, includes following step:
1.1.1 according to the threedimensional model of casting, wax-pattern model, and Preliminary design mold former are designed;
1.1.2 surface grids and volume mesh is carried out using numerical simulation software dividing, formed can be used for simulating with grid
Wax-pattern model and mold former, the side length 3mm of the wax-pattern surface grids and volume mesh, to guarantee wax-pattern simulation precision;
1.1.3 wax-pattern simulating boundary parameter is set;
1.1.4 different wax-pattern preparation technology parameters are set, wax-pattern preparation process are simulated, wherein mold preheating temperature
It is 25~50 DEG C, injection temperature is 55~85 DEG C, and injection pressure is 0.5~2MPa, and the dwell time is 150s~500s, above-mentioned
In parameter area, according to the wax-pattern structure developed, different technical parameters combination is selected, wax pattern surface current mark is evaluated, carries out work
Skill parameter optimization.By simulation, wax-pattern injection temperature is selected between 65~85 DEG C, and the preheating temperature of mold is controlled 30~50
Between DEG C, injection pressure is 0.9~1.3MPa, and when the dwell time is 250s~500s, the current mark and defect of wax pattern surface are less.
1.1.5 it according to the analog result of step 1.1.4, observes in wax-pattern cavity filling process, the flowing side of wax-pattern in a mold
To with fill type sequence, pass through change mold injection port design position, come change the flowing of wax-pattern and fill type sequence, reduce wax-pattern
Turbulent flow steadily sequentially fills type, and determines the design position and final mold former design scheme of mold injection port.Mold injection port
The selection of position has large effect to wax pattern surface current mark and internal flaw, passes through wax-pattern analog selection preferably mould
Have injection port position, reduce volume gas inside wax-pattern turbulent flow bring wax-pattern, locally fills type deficiency and surface defect, can further mention
Rise wax pattern surface and internal soundness.
When casting mouth design casting side length be 310 × 460mm face center, by the way of lateral, lead to
Simulation is crossed it is found that wax liquor cavity filling process long flow path, crosses to form turbulent flow after replicated structures.When casting mouth designs on casting side
Type, by simulation it is found that wax liquor turbulent flow is reduced, is filled by the way of the injection of bottom surface in the face center of a length of 900 × 460mm
It is relatively steady.Therefore the mode of casting mouth is arranged in bottom surface in selection, and designs mold.
1.1.6 on the basis of the mold former design scheme that step 1.1.5 is determined, repeat step 1.1.4, according to
The analog result prediction wax-pattern defect of step 1.1.4 generates position, and the wax-pattern after further set-up procedure 1.1.4 optimization prepares work
Ratio of defects is reduced by 10% or more, determines final wax-pattern preparation technology parameter by skill parameter.
Finally determining wax-pattern preparation technology parameter are as follows: the temperature of mold preheating is 35 DEG C, and injection temperature is 72 DEG C, injection
Pressure is 1.1MPa, dwell time 300s.This parameter is selected, the ratio of defects of wax-pattern can reduce by 12%, and wax-pattern ratio of defects reduces,
Destruction when can reduce wax-pattern reparation amount and wax-pattern reparation to initial surface, is conducive to the surface quality for improving wax-pattern.
1.2 prepare wax-pattern, according to Wax mold and wax-pattern preparation technology parameter that step 1.1 determines, prepare wax-pattern;
1.3 wax-pattern reparations, repair the position on wax-pattern there are surface defect, include following step:
1.3.1 the position equating that wax-pattern need to be repaired;
The region that wax pattern surface need to be repaired is carried out by the way of brushing reparation mould material or repeatedly drippage reparation mould material
It repairs, so that the sunk area of wax pattern surface is repaired mould material and fill up or the micro- fusing of the elevated regions of wax pattern surface, then should
The region equating that wax pattern surface need to be repaired.
The size in the region that wax pattern surface need to be repaired is with the outermost side profile of surface indentation region or surface raised areas
Basis, extend outwardly certain size, and the size of heat affected area is repaired by control wax-pattern, avoids restoring area too small, after reparation
Can exist and repair surface local dent, or reparation area is excessive, the heat affected area for repairing surface is excessive, influences wax pattern surface matter
Amount;
It carries out the region that wax pattern surface need to be repaired to repair repeatedly drippage reparation mould material by the way of brushing reparation mould material
Mode, so that the sunk area of wax pattern surface is repaired mould material and fill up or the micro- fusing of the elevated regions of wax pattern surface, then will
The region equating that the wax pattern surface need to be repaired.Need restoring area for the predominantly similar round and linear defect of shape, and ruler
It is very little larger.
For similar circular defect, diameter d > 10mm, it is surface indentation area that wax pattern surface, which needs the size of restoring area,
The outermost side profile of domain or surface raised areas extends 15mm around;
For similar linear defect, 8mm is extended around with the linear outermost profile in minor axis direction.
1.3.2 position is repaired with sand paper polishing wax-pattern, when polishing carries out according to the granularity point three-level of sand paper, using different shaped
Number sand paper area repaired to wax pattern surface polished step by step, it is first thick after carefully;
Wax-pattern repairs sand paper model used are as follows: 600 mesh of first order sand paper model, second level sand paper model is between 1000
Mesh, third level sand paper model is between 1500 mesh.Wax pattern surface intensity is low, and thicker sand paper cannot not only reach polishing wax pattern surface
Effect, can scratch wax pattern surface instead, improve Surface Roughness of wax Patterns by wax-pattern repair sand paper granularity it is specific by
Grade selection and design, so as to effective guarantee wax-pattern repairing quality and remediation efficiency.
1.3.3 wax-pattern is cleaned.
The specific steps of wax-pattern cleaning are as follows: first impregnated using clear water, then impregnated with organic reagent, finally rushed with clear water
It washes.Wherein organic reagent uses propyl alcohol and alcohol;Clear water impregnates selection and uses ultrasonic vibration.
The design of step 2 casting moulding system carries out simulation point to Filling Processes of Castings process of setting using the method for numerical simulation
Analysis, the running gate system of designing cast;
Filling Processes of Castings process of setting is simulated using numerical simulation software, and casting defect is predicted, the casting of design
Ratio of defects of the system Jing Guo numerical Simulation Prediction need to be lower than 8%, and detailed process is as follows:
(1) smelting and pouring technological parameter, including shell preheating temperature, pouring temperature, centrifugal rotational speed are set;
(2) mold filling and solidification processes temperature field simulation is carried out to casting, prediction casting defect generates position;
(3) pouring and riser systems position and casting process parameters are adjusted, emphasis reduces the quantity of the above shrinkage cavity defect of diameter 3mm,
Or the size of defect is reduced, until ratio of defects is lower than 8%.The shrinkage cavity defect of 3mm or more can not by specially treated technique into
The not damaged formula reparation of row, can only carry out exclusion reparation by way of destroying surface, have biggish shadow to surface roughness
It rings, thus passes through simulation and forecast and reduce ratio of defects and advantageously reduce later period casting defect reparation, and then promote cast(ing) surface light
Cleanliness.
It is prepared by the wax-pattern of step 3 Strip casting system, according to the casting moulding system scheme of Numeric simulation design in step 2,
Complete wax-pattern and running gate system combination;It is repaired using repairing identical mode with wax-pattern and carrying out the wax pattern surface defect of Strip casting system
It is multiple;
Surface reconditioning is carried out to the position of wax-pattern group weldering running gate system, which is repaired to the side of mould material using repeatedly drippage
Formula is repaired, and so that the sunk area of wax pattern surface is repaired mould material and is filled up or the micro- fusing of the elevated regions of wax pattern surface, so
The region equating that the wax pattern surface need to be repaired afterwards.Restoring area extends outwardly 10mm.
Wax-pattern repairs sand paper model used are as follows: 600 mesh of first order sand paper model, second level sand paper model is between 1000
Mesh, third level sand paper model is between 1500 mesh.
The preparation of step 4 shell carries out shell preparation using the wax-pattern of Strip casting system;
Step 5 casting pouring, preheats shell, then carries out casting pouring, prepares casting;
The preheating temperature of shell is 120 DEG C before casting pouring, keeps the temperature 2 hours.
According to the structure and weight of casting, casting pouring electric current 20KA is poured voltage 50V, melting vacuum degree≤6.0Pa,
5 hours cooling times of casting, the combination selection and control of above-mentioned parameter are conducive to the control of cast(ing) surface oxidated layer thickness, from
And improve surface finish of casting.
Blast of step 6 carries out the processing of surface blast to the casting after removal running gate system;Using the sand of 60 mesh;
Titanium alloy glass lubricant can be sprayed on cast(ing) surface, improve blast effect.
Sand material uses quartz sand.The pressure of blast is 1MPa, so as to effective guarantee blast efficiency and effect, together
When avoid surface from blast damage occur.
Step 7 pickling carries out process processing to the casting after a blast, carries out surface acid-washing afterwards, and casting is thick after pickling
The removal amount 4mm of degree.Pickling solution is HNO3The mixed solution of+HF+ additive.
Two blasts of step 8 carry out the processing of surface blast to the casting after pickling;Using the sand of 80~250 mesh, divide more
Secondary, multi-level blast from thick to thin;
In secondary blast, three-level granularity is divided to carry out blast, it is primary that every grade of granularity at least carries out blast;Wherein 80 mesh are first
Grade granularity, 160 mesh are second level granularity, and 200 mesh are third level granularity;After every grade of granularity blast, surface roughness are detected,
According to surface roughness value and qualification rate, the granularity of next stage is judged, until surface roughness meet the requirements.
80~120 mesh blast rear surface roughness≤3 μm, 120~200 mesh blast rear surface roughness≤2.5 μm, 200
~250 mesh blast rear surface roughness≤2 μm.
After first order blast, the region after cast(ing) surface blast is detected, taking a position includes the outer of blast region
Portion, middle part and inside take quantity a little to be determined according to blast area size, take at random a little;Take the rough surface degree of a position
When value meets current level granularity corresponding surface roughness value, for qualification, statistics takes the qualification rate of a position, qualified at this time
Rate is 82%, can carry out the granularity blast of second level;
After the blast of the second level, the region after cast(ing) surface blast is detected, taking a position includes the outer of blast region
Portion, middle part and inside take quantity a little to be determined according to blast area size, take at random a little;Take the rough surface degree of a position
When value meets current level granularity corresponding surface roughness value, for qualification, statistics takes the qualification rate of a position, qualified at this time
Rate is 76%, can carry out the granularity blast of third level, until surface roughness reaches requirement.It is detected, works as surface roughness
Stop blast at≤2 μm.
In secondary blast step, sand material uses one or more of bead, silicon carbide, Brown Alundum, quartz sand.It is secondary
The blast pressure of blast is 2MPa.