CN1129199A

CN1129199A - Process for one-step sintering carborundum recrystallized product by cold-extrusion forming

Info

Publication number: CN1129199A
Application number: CN 95100358
Authority: CN
Inventors: 薛天瑞
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-16
Filing date: 1995-02-16
Publication date: 1996-08-21

Abstract

The once-fired silicon carbide recrystallized product is made up by using silicon carbide as main material, using graphite powder, carbon black and polyvinyl alcohol as auxiliary materials, mixing at ordinary temp., vacuum extrusion moding oven-drying, baking, soaking in bitumen and once-firing at 2100-2200 deg.C. Said product is non-laminated, free from crescent pores and uniform in density. As compared with existent production method, its production cycle is shortened, and its energy consumption is greatly reduced.

Description

A kind of method of cold extrusion shaped once-firing of silicon carbide recrystallize goods

The present invention relates to a kind of method of cold extrusion shaped once-firing of silicon carbide recrystallize goods.

The silicon carbide recrystallize goods of domestic current; as square beam; protective tube and rolling bar etc.; they all adopt pitch to do caking agent; adopt steam or electrically heated, under greater than 200 ℃ temperature, carry out hot batch mixing; hot extrusion molding is biscuiting and burning till under greater than 2000 ℃ temperature for twice under 1000 ℃-1200 ℃ temperature then.The fair length of its technical process is complicated, power consumption is big, and yield rate is low, and product layering and crescent moon pore are serious, have reduced the intensity and the work-ing life of product.

The object of the present invention is to provide a kind of can be when producing silicon carbide recrystallize goods the reduction of erection time, cut down the consumption of energy significantly, improve the quality of products and the method for the cold extrusion shaped once-firing of a kind of silicon carbide recrystallize goods of finished product rate.

The mode that the present invention realizes is that it is major ingredient with silicon carbide, wherein 80 purposes account for that weight 40%, 120 purposes account for weight 20%, 180 purposes account for weight 40%, other batching genus adds, the part by weight that accounts for major ingredient respectively is that Graphite Powder 99 accounts for 2.5%, carbon black accounts for 2%, polyvinyl alcohol accounts for 6%, batch mixing, extrusion under vacuum at normal temperatures, under 40 ℃-50 ℃ temperature, dry, baking place under 300 ℃-350 ℃ temperature, with the base substrate impregnate with bitumen after baking place, burn till then 2100 ℃-2200 ℃ temperature next time.

The invention has the advantages that it has adopted batch mixing under the normal temperature, extrusion under vacuum, the method of next time burning till through low temperature baking place and high temperature, its product does not have layering, no crescent moon pore, so guaranteed that product density is very even, the intensity of product and the yield rate of product have been improved effectively, shorten the production cycle, reduced energy consumption significantly.Production cycle of product was shortened to by original 42 days have only about 8 days, integrated yield is brought up to more than 80% by original 30-40%, and coal consumption is 0, and power consumption has only 1/3 of former technology.Under the situation of producing 1 kiloton per year, former technology needs about 250 people, and the present invention only needs about 30 people, and production cost is reduced to has only 1/3 1 1/4 of former technology.

The present invention is further described with embodiment below:

The present invention adopts following method steps:

1. the batching of selecting materials: the present invention is major ingredient with silicon carbide, wherein 80 purpose weight account for 40%, 120 purpose weight and account for 20%, 180 purpose weight and account for 40%, other part by weight that adds that batching accounts for major ingredient respectively is that Graphite Powder 99 accounts for 2.5%, carbon black accounts for 2%, polyvinyl alcohol accounts for 6%, polyvinyl alcohol: water=1: 4 is water-soluble.

2. batch mixing: earlier siccative is put at normal temperatures mix in the mixer after, stir adding caking agent.

3. extrusion under vacuum: use the vacuum extruder extrusion molding at normal temperatures.

4. oven dry: under 300 ℃ of-50 ℃ of temperature; In drying shed, dry.

5. baking place: under 300 ℃-350 ℃ temperature, in the iron case, bury real baking place 7-8 hours with carbon granules.

6. impregnate with bitumen: the base substrate that baking place is crossed carries out impregnate with bitumen with 200-250 ℃ pitch.

7. burn till: in resistance furnace with under 2100 ℃ of-2200 ℃ of temperature, once-firing, the time is 21-22 hours.

Claims

1. the method for the cold extrusion shaped once-firing of silicon carbide recrystallize goods, it is characterized in that it is major ingredient with silicon carbide, wherein 80 purposes account for weight 40%, 120 purposes account for weight 20%, 180 purposes account for weight 40%, other batching genus adds, the part by weight that accounts for major ingredient respectively is that Graphite Powder 99 accounts for 2.5%, carbon black accounts for 2%, polyvinyl alcohol accounts for 6%, batch mixing at normal temperatures, extrusion under vacuum is dried under 40 ℃-50 ℃ temperature, baking place under 300 ℃-350 ℃ temperature, with the base substrate impregnate with bitumen after baking place, burn till then 2100 ℃-2200 ℃ temperature next time.