Summary of the invention
The deficiency that exists in order to overcome above-mentioned prior art, the object of the present invention is to provide the casting technique under a kind of condition of negative pressure, the present invention combines the advantage of model casting and lost foam casting, both utilized the high-quality casting mold of model casting, and under the pattern of fever condition, pour into a mould, utilized again the negative pressure technique of evaporative pattern, around the model casting casting mold, form subnormal ambient, reduce the secondary oxidation of metal, and pressure differential interior with type and the cast gate place, promote metal to fill type and raising molten metal feeding capacity, thereby obtain higher-quality foundry goods.
In order to achieve the above object, the technical solution adopted in the present invention is:
Casting technique under a kind of condition of negative pressure, at first with the shell 1 of investment casting method preparation with cast gate 6, shell 1 is pressed the predetermined time roasting to predetermined sintering temperature, be cooled to room temperature and put into again heat-resisting sandbox 2 with bleeding point 4, perhaps will directly place with the shell 1 of investment casting method preparation the heat-resisting sandbox 2 with bleeding point 4, fire resistant heat preserving sand 3 is inserted in gap between shell 1 and heat-resisting sandbox 2, temperature resistant encapsulation layer 5 in fire resistant heat preserving sand 3 surface coverage preset thickness, and cast gate 6 tops of shell 1 are exposed on the temperature resistant encapsulation layer 5, such shell 1, heat-resisting sandbox 2, fire resistant heat preserving sand 3 and temperature resistant encapsulation layer 5 have consisted of casting mold, this casting mold is placed heating furnace, simultaneously be heated to default heating-up temperature according to technological requirement, the casting mold that is heated to default heating-up temperature is taken out from heating furnace, bleeding point 4 is connected air extractor, by air extractor to bleeding in the casting mold, with the pressure setting in the casting mold under default condition of negative pressure, then inject cast gate 6 by the default molten metal that will melt, subsequently wait the molten metal that injects cast gate 6 solidify be cooled to room temperature after, molten metal has just formed foundry goods, takes out at last foundry goods from casting mold.
Described molten metal is molten stainless steel, carbon steel liquid, aluminum alloy melt, copper alloy liquid or liquid magnesium alloy.
The advantage of model casting and lost foam casting is combined, both utilized the high-quality casting mold of model casting, and under the pattern of fever condition, pour into a mould, utilized again the negative pressure technique of evaporative pattern, form subnormal ambient around the model casting casting mold, reduce the secondary oxidation of metal, and with the pressure differential of mistake with the cast gate place, promote metal to fill type and raising molten metal complementary capabilities, thereby obtain higher-quality foundry goods.
The specific embodiment
The present invention will be described in more detail below in conjunction with drawings and Examples.
Embodiment 1:
As shown in drawings, casting technique under the condition of negative pressure of present embodiment, at first with the shell 1 of investment casting method preparation with cast gate 6, shell 1 is pressed the roasting of 30 minutes predetermined times to 1050 ℃ of predetermined sintering temperatures, be cooled to room temperature and put into again heat-resisting sandbox 2 with bleeding point 4, perhaps will directly place with the shell 1 of investment casting method preparation the heat-resisting sandbox 2 with bleeding point 4, fire resistant heat preserving sand 3 is inserted in gap between shell 1 and heat-resisting sandbox 2, temperature resistant encapsulation layer 5 in fire resistant heat preserving sand 3 surface coverage preset thickness, and cast gate 6 tops of shell 1 are exposed on the temperature resistant encapsulation layer 5, such shell 1, heat-resisting sandbox 2, fire resistant heat preserving sand 3 and temperature resistant encapsulation layer 5 have consisted of casting mold, this casting mold is placed heating furnace, be heated to 1000 ℃ of default heating-up temperatures according to technological requirement simultaneously, the casting mold that is heated to default heating-up temperature is taken out from heating furnace, bleeding point 4 is connected air extractor, by air extractor to bleeding in the casting mold, with the pressure setting in the casting mold under default condition of negative pressure, then inject cast gate 6 by the default molten metal that will melt, subsequently wait the molten metal that injects cast gate 6 solidify be cooled to room temperature after, molten metal has just formed foundry goods, takes out at last foundry goods from casting mold.Described molten metal is molten stainless steel.
Embodiment 2:
As shown in drawings, casting technique under the condition of negative pressure of present embodiment, at first with the shell 1 of investment casting method preparation with cast gate 6, shell 1 is pressed the roasting of 30 minutes predetermined times to 1050 ℃ of predetermined sintering temperatures, be cooled to room temperature and put into again heat-resisting sandbox 2 with bleeding point 4, perhaps will directly place with the shell 1 of investment casting method preparation the heat-resisting sandbox 2 with bleeding point 4, fire resistant heat preserving sand 3 is inserted in gap between shell 1 and heat-resisting sandbox 2, temperature resistant encapsulation layer 5 in fire resistant heat preserving sand 3 surface coverage preset thickness, and cast gate 6 tops of shell 1 are exposed on the temperature resistant encapsulation layer 5, such shell 1, heat-resisting sandbox 2, fire resistant heat preserving sand 3 and temperature resistant encapsulation layer 5 have consisted of casting mold, this casting mold is placed heating furnace, be heated to 900 ℃ of default heating-up temperatures according to technological requirement simultaneously, the casting mold that is heated to default heating-up temperature is taken out from heating furnace, bleeding point 4 is connected air extractor, by air extractor to bleeding in the casting mold, with the pressure setting in the casting mold under default condition of negative pressure, then inject cast gate 6 by the default molten metal that will melt, subsequently wait the molten metal that injects cast gate 6 solidify be cooled to room temperature after, molten metal has just formed foundry goods, takes out at last foundry goods from casting mold.Described molten metal is carbon steel liquid.
Embodiment 3:
As shown in drawings, casting technique under the condition of negative pressure of present embodiment, at first with the shell 1 of investment casting method preparation with cast gate 6, shell 1 is pressed the roasting of 30 minutes predetermined times to 1050 ℃ of predetermined sintering temperatures, be cooled to room temperature and put into again heat-resisting sandbox 2 with bleeding point 4, perhaps will directly place with the shell 1 of investment casting method preparation the heat-resisting sandbox 2 with bleeding point 4, fire resistant heat preserving sand 3 is inserted in gap between shell 1 and heat-resisting sandbox 2, temperature resistant encapsulation layer 5 in fire resistant heat preserving sand 3 surface coverage preset thickness, and cast gate 6 tops of shell 1 are exposed on the temperature resistant encapsulation layer 5, such shell 1, heat-resisting sandbox 2, fire resistant heat preserving sand 3 and temperature resistant encapsulation layer 5 have consisted of casting mold, this casting mold is placed heating furnace, be heated to 700 ℃ of default heating-up temperatures according to technological requirement simultaneously, the casting mold that is heated to default heating-up temperature is taken out from heating furnace, bleeding point 4 is connected air extractor, by air extractor to bleeding in the casting mold, with the pressure setting in the casting mold under default condition of negative pressure, then inject cast gate 6 by the default molten metal that will melt, subsequently wait the molten metal that injects cast gate 6 solidify be cooled to room temperature after, molten metal has just formed foundry goods, takes out at last foundry goods from casting mold.Described molten metal is aluminum alloy melt.
Embodiment 4:
As shown in drawings, casting technique under the condition of negative pressure of present embodiment, at first with the shell 1 of investment casting method preparation with cast gate 6, shell 1 is pressed the roasting of 30 minutes predetermined times to 1050 ℃ of predetermined sintering temperatures, be cooled to room temperature and put into again heat-resisting sandbox 2 with bleeding point 4, perhaps will directly place with the shell 1 of investment casting method preparation the heat-resisting sandbox 2 with bleeding point 4, fire resistant heat preserving sand 3 is inserted in gap between shell 1 and heat-resisting sandbox 2, temperature resistant encapsulation layer 5 in fire resistant heat preserving sand 3 surface coverage preset thickness, and cast gate 6 tops of shell 1 are exposed on the temperature resistant encapsulation layer 5, such shell 1, heat-resisting sandbox 2, fire resistant heat preserving sand 3 and temperature resistant encapsulation layer 5 have consisted of casting mold, this casting mold is placed heating furnace, be heated to 800 ℃ of default heating-up temperatures according to technological requirement simultaneously, the casting mold that is heated to default heating-up temperature is taken out from heating furnace, bleeding point 4 is connected air extractor, by air extractor to bleeding in the casting mold, with the pressure setting in the casting mold under default condition of negative pressure, then inject cast gate 6 by the default molten metal that will melt, subsequently wait the molten metal that injects cast gate 6 solidify be cooled to room temperature after, molten metal has just formed foundry goods, takes out at last foundry goods from casting mold.Described molten metal is copper alloy liquid.
Embodiment 5:
As shown in drawings, casting technique under the condition of negative pressure of present embodiment, at first with the shell 1 of investment casting method preparation with cast gate 6, shell 1 is pressed the roasting of 30 minutes predetermined times to 1050 ℃ of predetermined sintering temperatures, be cooled to room temperature and put into again heat-resisting sandbox 2 with bleeding point 4, perhaps will directly place with the shell 1 of investment casting method preparation the heat-resisting sandbox 2 with bleeding point 4, fire resistant heat preserving sand 3 is inserted in gap between shell 1 and heat-resisting sandbox 2, temperature resistant encapsulation layer 5 in fire resistant heat preserving sand 3 surface coverage preset thickness, and cast gate 6 tops of shell 1 are exposed on the temperature resistant encapsulation layer 5, such shell 1, heat-resisting sandbox 2, fire resistant heat preserving sand 3 and temperature resistant encapsulation layer 5 have consisted of casting mold, this casting mold is placed heating furnace, be heated to 750 ℃ of default heating-up temperatures according to technological requirement simultaneously, the casting mold that is heated to default heating-up temperature is taken out from heating furnace, bleeding point 4 is connected air extractor, by air extractor to bleeding in the casting mold, with the pressure setting in the casting mold under default condition of negative pressure, then inject cast gate 6 by the default molten metal that will melt, subsequently wait the molten metal that injects cast gate 6 solidify be cooled to room temperature after, molten metal has just formed foundry goods, takes out at last foundry goods from casting mold.Described molten metal is liquid magnesium alloy.