CN101698489B - Method for making magnesium oxide octahedron - Google Patents

Abstract

The invention belongs to the technical field of method for making magnesium oxide octahedron used as voltage transmitting medium in high voltage experience. The method for making magnesium oxide octahedron includes mixing, casting moulding and sintering; dried magnesium oxide power and adhesive are mixed and stirred for 3-5 minutes; mixed liquid of magnesium oxide powder and adhesive is rapidly cast into a moulding mould under vibration, vibration is continued for 1-5 minutes after casting to remove air bubbles, and then standing is carried out for 2-3 hours and midbody is taken out; the midbody of magnesium oxide octahedron is placed into a warming furnace to be continuously heated to 190-210 DEG C at warming rate of 5-7 DEG C per hour, and then the temperature is maintained for 45-48 hours and sintering is carried out to obtain finished product. The invention has the advantages of simple operation, lower cost, low labour intensity and higher product dimensional precision.

Description

A kind of method for making magnesium oxide octahedron

Technical field

The present invention relates to a kind of octahedral preparation method, in particular for the High-Voltage Experimentation method for making magnesium oxide octahedron.

Background technology

Fields such as some scientific research institutions, laboratory at home at present, scientific experiment are with the octahedra large usage quantity of magnesia, and in particular for High-Voltage Experimentation, because its pressure transmission performance is good, and insulation, heat-proof quality are good, make the transmission medium of High-Voltage Experimentation with the magnesia octahedron.

Existing octahedron mainly obtains by machining magnesia round bar method.Exist that difficulty of processing is big, dimensional accuracy is lower, a large amount of magnesia raw material of waste, cost are than problems such as height.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of simple and practical method for making magnesium oxide octahedron, to overcome the shortcoming of background technology.

For achieving the above object, adopt the technical scheme of following steps:

Prepare the oven dry magnesium oxide powder; Prepare adhesive.Make feedstock production magnesia octahedron with magnesium oxide powder and adhesive.The model that adhesive wherein can select for use U.S. AREMCO PRODUCTS company to produce is the series of products of Ceramacast 584-OF, this product has different model, and the solid model is that Ceramacast 584-OF-S, liquid model are that Ceramacast 584-OF-L, Powdered model are Ceramacast 584-OF-P.The used adhesive model of the present invention is Ceramacast584-OF-L, and liquid is creamy white.

To dry magnesium oxide powder and be uniformly mixed into pasty state liquid by the certain mass ratio with adhesive.

Magnesium oxide powder and the even mixing material of adhesive are cast in mould fast, solidify the back and obtain the octahedral intermediate of magnesia.

The octahedral intermediate of sintered magnesia in automatic condition heating furnace makes adhesive volatilization burn off, slowly cools to room temperature afterwards in air, obtains the final products with certain degree of hardness of the octahedral bodily form.

Concrete technical scheme of the present invention is:

A kind of method for making magnesium oxide octahedron has the process of batch mixing, moulding by casting, sintering;

Described batch mixing process is that the magnesium oxide powder of will dry mixes by mass ratio 5: 1.85～2 with adhesive, puts into mixer and stirs for 3～5 seconds;

Described moulding by casting process, be that mixing material with magnesium oxide powder and adhesive was cast in the mould in 2～5 seconds, keep concussion in the cast, continue behind the casting complete to shake for 1～5 second, to get rid of bubble, tranquil again the placement after 2～3 hours taken out, and obtains the octahedral intermediate of magnesia;

Described sintering process is that the octahedral intermediate of magnesia is put into heating furnace, is warming up to 190～210 ℃ continuously with 5～7 ℃/hour heating rates, and constant temperature is 45～48 hours again, sinters the magnesia octahedron into.

Magnesium oxide powder used in the present invention, purity are preferably more than 98%, and granularity is preferably 100～120 orders; And, make it dry through 120～130 ℃ of insulation bakings in 48～50 hours down.

The adhesive that U.S. AREMCO PRODUCTS company produces has different models.As adhesive of the present invention, can select model is the product of Ceramacast 584-OF-L, is the proper product of concentration.Can also select two kinds of type products to mix and use, mix use by mass ratio 5: 2～3 such as two kinds of adhesives that are respectively Ceramacast584-OF-P and Ceramacast 584-OF-L.

The present invention has simple to operate, and cost is lower, and labour intensity is low, and the product size precision is than advantages such as height.

Description of drawings

Fig. 1 is a mould user mode schematic diagram of the present invention.

Fig. 2 is the elevation cross-sectional view of mould of the present invention.

Fig. 3 is the A-A face profile of Fig. 2.

Fig. 4 is final products shape figure.

The specific embodiment

Below in conjunction with accompanying drawing the specific embodiment of the invention is described in more detail.

Embodiment 1

Fig. 1 provides mould user mode figure of the present invention.Fig. 2 provides the front view of mould of the present invention.Fig. 3 provides A-A profile among Fig. 2.In the accompanying drawing, 1 is module, and 2 is lucite, and 3 is the mould inner chamber, and 4 is oscillator.

Mould is made up of eight identical modules and six lucite, and every module is a material with polytetrafluoroethyl-ne fat all, because of its smooth surface and intensity is preferably arranged.The shape of every module is that a square or cuboid remove an angle and form, remove behind the angle rib that forms at square or adjacent three faces of cuboid and constitute equilateral triangle, and rib long (being the length of side of equilateral triangle) to equal the rib of the octahedral gore of required magnesia long.

Embodiment 2

Provide the process of 12 millimeters magnesia octahedrons of preparation (the side triangle length of side is 12 millimeters).

The selective oxidation magnesium dust, white, purity are more than 98%, and is pollution-free.Granularity is 100～120 orders.Take out after in 120～130 ℃ of stoves, toasting 48～50 hours, obtain drying magnesium oxide powder.

Selecting model is Ceramacast 584-OF-L, and milky white liquid is done adhesive.

Measure oven dry magnesium oxide powder 11.25 grams and mix at ambient temperature, put into mixer, stirred for 5 seconds, make magnesium oxide powder and adhesive become even mixing material, in the pasty state with 150r/min with adhesive 4.31 grams.

Even mixing material is cast in the mould that embodiment 1 provides, and module gore rib length is 12 millimeters.Cast should be finished in as 2～5 seconds in the short period, continued 1～3 second of concussion after finishing, and got rid of bubble, and tranquil again the placement taken out the octahedral intermediate of magnesia that solidifies after 2～3 hours;

Will carry out sintering at last, with the octahedra intermediate of the magnesia of coagulation forming, put into automatic condition heating furnace, heat up automatically continuously with 5～7 ℃/hour, after fire box temperature reached 200 ℃, constant temperature continued baking 45～48 hours.The oven dry back slowly cools to room temperature in air, obtain product.

The shape figure of final products sees Fig. 4.

Embodiment 3

Provide the process of 8 millimeters magnesia octahedrons of preparation (the side triangle length of side is 8 millimeters).

Selective oxidation magnesium dust and oven dry, selection adhesive are with embodiment 2.Measure oven dry magnesium oxide powder 5.31 grams and mix at ambient temperature, put into mixer, stirred for 4 seconds, make magnesium oxide powder and adhesive become even mixing material with 150r/min with adhesive 2.01 grams.Later cast, sintering process are with embodiment 2, and use module gore rib length is 8 millimeters mould when just pouring into a mould.

Embodiment 4

Provide the process of 6 millimeters magnesia octahedrons of preparation (the side gore length of side is 6 millimeters).

Selective oxidation magnesium dust and oven dry, selection adhesive are with embodiment 2.Measure oven dry magnesium oxide powder 4.05 grams and mix at ambient temperature, put into mixer, stirred for 3 seconds, make magnesium oxide powder and adhesive become even mixing material with 150r/min with adhesive 1.61 grams.Later cast, sintering process are with embodiment 2, and use module gore rib length is 6 millimeters mould when just pouring into a mould.

Embodiment 5

In embodiment 2,3,4, model is that the adhesive of Ceramacast 584-OF-L can be respectively two kinds of adhesives of Ceramacast 584-OF-P and Ceramacast 584-OF-L with model and substitutes by the liquid that mass ratio 5: 2～3 at room temperature mixes.

Embodiment 6

In embodiment 2～5, also the magnesium oxide powder of oven dry can be mixed by mass ratio 5: 1.85～2 with adhesive, put into 3～5 seconds of mixer stirring after, fill with in the mould of required big or small inner chamber, exhaust again, solidify, sinter into product.The good raw material of not necessarily first weighing mixes, and the mixing material of suitable quality is all handed over annotated in the mould.

Claims (2)

1. method for making magnesium oxide octahedron has the process of batch mixing, moulding by casting, sintering;

Described batch mixing process is that the magnesium oxide powder of will dry mixes by mass ratio 5: 1.85～2 with adhesive, puts into mixer and stirs for 3～5 seconds;

Described moulding by casting process, be that mixing material with magnesium oxide powder and adhesive was cast in the mould in 2～5 seconds, keep concussion in the cast, continue behind the casting complete to shake for 1～5 second, to get rid of bubble, tranquil again the placement after 2～3 hours taken out, and obtains the octahedral intermediate of magnesia; Described adhesive, be that the model that U.S. AREMCO PRODUCTS company produces is the product of Ceramacast584-OF-L, or two kinds of adhesives that the model that U.S. AREMCO PRODUCTS company produces is respectively Ceramacast 584-OF-P and Ceramacast 584-OF-L are mixed use by mass ratio 5: 2～3;

Described sintering process is that the octahedral intermediate of magnesia is put into heating furnace, is warming up to 190～210 ℃ continuously with 5～7 ℃/hour heating rates, and constant temperature is 45～48 hours again, sinters the magnesia octahedron into.

2. method for making magnesium oxide octahedron according to claim 1 is characterized in that, described magnesium oxide powder, and purity is more than 98%, granularity is 100～120 orders; Through 120～130 ℃ of insulation bakings in 48～50 hours down.

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