Method for improving poriness of alumina ceramic mold core

A technology of alumina ceramics and porosity, which is applied to ceramic products, other household appliances, household appliances, etc., can solve the problems of insignificant effect, difficulty in core removal of alumina ceramic cores, and sintering deformation of cores, and achieve core removal. Improve performance, ensure high temperature performance, increase the effect of sintering shrinkage

Inactive Publication Date: 2012-06-13
SHENYANG LIMING AERO-ENGINE GROUP CORPORATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Alumina ceramic cores have better high-temperature performance than silicon-based cores, and are widely used in the development and production of turbine blades with complex inner cavity structures, but the difficulty of removing alumina ceramic cores has always been its engineering application.
But when the addition of graphite exceeds 2wt% of the total amount of the core formula, the firing shrinkage of the core will exceed 1.5%, which will cause serious sintering deformation of the core; and the effect of this core porosity improvement method is not obvious, The maximum porosity of the core can only be increased by 2%

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] (1) Preparation of core slurry: 39wt% fused corundum powder, 60wt% α-Al 2 o 3 Porous additive and 1wt% mineralizer TiO 2 Add it into the ball mill tank, in which the particle size of the fused corundum powder is 30-80 μm, which belongs to α-Al 2 o 3 The particle size of the porous additive is 1 μm, and the ball milling time is 2 hours to form a core material; a plasticizer accounting for 15% of the core material weight is added to the mixer, and the plasticizer formula is: paraffin wax 93%, beeswax 5%, polyethylene 2 %, heated to 110°C; then the core material was added to the mixer and stirred for 20 hours to form a core slurry;

[0029] (2) Compression of the core: Press the core slurry on the core injection machine to form the core, keep the material temperature at 95°C, the pressing pressure at 2MPa, and the holding time for 20s;

[0030] (3) Roasting of the core: heat the core at 200°C for 4 hours, heat it up to 400°C for 2 hours, then heat it up to 600°C for 2...

Embodiment 2

[0036] (1) Preparation of core slurry: 69wt% fused corundum powder, 30wt% α-Al 2 o 3 Porous additive and 1wt% mineralizer TiO 2 Add it into the ball mill tank, in which the particle size of the fused corundum powder is 80μm, which belongs to α-Al 2 o 3 The particle size of the porous additive is 30 μm, and the ball milling time is 2 hours to form a core material; a plasticizer accounting for 20% of the core material weight is added to the mixer, and the plasticizer formula is: paraffin wax 93%, beeswax 5%, polyethylene 2 %, heated to 120°C; then the core material was added to the agitator and stirred for 20 hours to form a core slurry;

[0037] (2) Compression of the core: Press the core slurry on the core injection machine to form the core, keep the temperature of the material at 105°C, the pressing pressure at 4MPa, and the holding time for 20s;

[0038] (3) Roasting of the core: heat the core at 200°C for 4 hours, heat it up to 400°C for 2 hours, then heat it up to 600...

Embodiment 3

[0044] (1) Preparation of core slurry: 50wt% fused corundum powder, 49wt% α-Al 2 o 3 Porous additive and 1wt% mineralizer TiO 2 Add it into the ball mill tank, in which the particle size of the fused corundum powder is 50μm, which belongs to α-Al 2 o 3 The particle size of the porous additive is 25 μm, and the ball milling time is 2.2 hours to form a core material; a plasticizer accounting for 18% of the weight of the core material is added to the mixer, and the plasticizer formula is: paraffin wax 93%, beeswax 5%, polyethylene 2 %, heated to 115°C; then the core material was added to the mixer and stirred for 20 hours to form a core slurry;

[0045] (2) Compression of the core: Press the core slurry on the core injection machine to form the core, keep the temperature of the material at 100°C, the pressing pressure at 3MPa, and the holding time for 20s;

[0046](3) Roasting of the core: keep the core at 200°C for 4 hours, heat it up to 400°C for 2 hours, then heat it up t...

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Abstract

The invention relates to the technical field of preparation of ceramic, in particular to a method for improving the poriness of an alumina ceramic mold core. The technical scheme is as follows: feeding plasticizer which occupies 15 to 20 percent of core material by weight into a container with a stirrer and heating up to 100 to 120 DEG C; pressing mold core slurry into a mold core on an injection machine, insulating the mold core for 4 hours under the temperature of 200 DEG C, heating up to 400 DEG C and insulating for 2 hours, heating up to 600 DEG C and insulating for 2 hours, heating up to 900 DEG C and insulating for 2 hours, heating up to 1250 DEG C and insulating for 4 hours, and cooling down to 100 DEG C along with a furnace and taking out from the furnace; soaking the mold core in ethylsilicate digest with the viscosity of (3.6 to 8)*10<-6> Pa.s for 30 to 40 minutes, air drying for 24 hours and then ammonia drying for 30 minutes; placing the mold core which is strengthened for the first time in phenolic alcohol-soluble varnish, soaking for 2 to 3 hours under ambient temperature, and then air drying for 24 hours; and baking the strengthened mold core under the temperature of 150 DEG C for 2 hours to make the end product.

Description

technical field [0001] The invention relates to the technical field of ceramic preparation, in particular to a method for improving the porosity of an alumina ceramic core. Background technique [0002] Alumina ceramic cores have better high-temperature performance than silicon-based cores, and are widely used in the development and production of turbine blades with complex inner cavity structures, but the difficulty of removing alumina ceramic cores has always been its engineering application. The porosity is an important index to measure the core removal performance of the alumina ceramic core. The higher the porosity, the better the core removal performance, and vice versa. [0003] The formula of the existing alumina ceramic core is 99wt% fused corundum powder plus 1wt% mineralizer. The manufacturing process is pressed core-roasting-strengthening. The cores are all of this process, and the porosity of the AC-2 alumina ceramic core produced by this process is 37%, which ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B38/00
Inventor 张世东刘艳张明俊李琳
Owner SHENYANG LIMING AERO-ENGINE GROUP CORPORATION
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