CN104107879A - Ceramic secondary reinforcement method - Google Patents

Abstract

The invention relates to the field of precise casting of fusible patterns, and especially relates to a solution scheme of core breakage and leakage defects caused by insufficient ceramic core strength. A ceramic core secondary reinforcement method comprises the following steps: 1, secondary roasting of a de-waxed die shell with a ceramic core: heating from normal temperature to 900DEG C under a heating rate of 4-5DEG C/min, carrying out heat insulation for 1-2h, heating from 900DEG C to 1200DEG C under a heating rate of 3-4DEG C/min, carrying out heat insulation for 3-4h, cooling with a furnace to below 200DEG C, and discharging the obtained die shell from the furnace; and 2, secondary reinforcement on the secondary-roasted die shell with the ceramic: slowly dumping an ethyl silicate hydrolysate into the roasted die shell from the sprue cup of the die shell until the level of the ethyl silicate hydrolysate reaches the sprue cup, immersing for 20-40min, dumping out the ethyl silicate hydrolysate, naturally drying, and chemically hardening to obtain a die shell to be cast.

Description

Ceramic core secondary hardening method

Technical field

The present invention relates to precision-investment casting field, particularly relate to the solution of the disconnected leakage core defect causing because of ceramic core undercapacity.

Background technology

The intensity of ceramic core is the principal element that affects ceramic core performance.For making ceramic core can bear impact, the pressure of wax material in compacting wax-pattern, dewaxing, formwork roasting and casting process, the various external active forces such as the impact of molten metal, pressure, ceramic core need to carry out intensive treatment, traditional ceramic core high and low temperature reinforcement process, for the problems such as disconnected leakage core that solve smallclothes ceramic core, it is respond well.But for the ceramic core of large-scale blade, by its method, can not be satisfied with production requirement completely, the disconnected core problem of leaking still often occurs.Particularly, when the large hollow blade of production inner chamber especially complexity, because the elevated temperature strength of ceramic core is not enough, and the situation that causes foundry goods to be scrapped is many especially.

Summary of the invention

(1) goal of the invention

The object of the invention is by the ceramic core in formwork after dewaxing, to carry out secondary hardening further to improve ceramic core elevated temperature strength, reduces and even eliminate disconnected, the leakage core problem of foundry goods.

(2) invention technical scheme

The sintering when manufacturing ceramic core of the secondary hardening is here crossed once.Ceramic core secondary hardening method, this method comprises the following steps:

The first step, formwork after dewaxing with ceramic core is carried out to after baking, roasting technique is as follows: with the heating rate of 4-5 per minute ℃, from normal temperature, rise to 900 ℃, insulation 1-2 hour, with the heating rate of 3-4 per minute ℃, from 900 ℃, rise to 1200 ℃ again, insulation 3-4 hour, finally cools to 200 ℃ with the furnace and comes out of the stove below.

Second step, the formwork with ceramic core after after baking is carried out to secondary hardening, reinforcement process is as follows: silicate hydrolyzate liquid is slowly poured in the formwork after roasting from the cup of formwork, until flood to cup place, soak after 20～40 minutes, silicate hydrolyzate liquid is poured out, after natural drying and chemicosolidifying, it is to be cast that formwork gets final product etc. again.

(3) beneficial effect

The inventive method operating process is simple, and can effectively improve the elevated temperature strength of ceramic core, reduces disconnected generation of leaking core defect, and casting qualified rate is significantly improved, and has saved production cost, has produced huge economic benefit.

Accompanying drawing explanation

Fig. 1 is the artwork of this method.

The specific embodiment

Further illustrate by the following examples method of the present invention

Embodiment 1

The II level guide vane of certain machine of take is example.Implementation process is as follows: ceramic core secondary hardening method, and this method comprises the following steps:

The first step, formwork after dewaxing with ceramic core is carried out to after baking, roasting technique is as follows: with the heating rates of 4 ℃ per minute, from normal temperature, rise to 900 ℃, be incubated 1 hour, with the heating rate of 3 ℃ per minute, from 900 ℃, rise to 1200 ℃ again, be incubated 3 hours, finally cool to 200 ℃ with the furnace and come out of the stove below.

Second step, the formwork with ceramic core after after baking is carried out to secondary hardening, reinforcement process is as follows: silicate hydrolyzate liquid is slowly poured in the formwork after roasting from the cup of formwork, until flood to cup place, soak after 20 minutes, silicate hydrolyzate liquid is poured out, after natural drying and chemicosolidifying, it is to be cast that formwork gets final product etc. again.

Embodiment 2

The I level guide vane of certain machine of take is example.Implementation process is as follows:

Ceramic core secondary hardening method, this method comprises the following steps:

The first step, formwork after dewaxing with ceramic core is carried out to after baking, roasting technique is as follows: with the heating rates of 4.5 ℃ per minute, from normal temperature, rise to 900 ℃, be incubated 1.5 hours, with the heating rate of 3.5 ℃ per minute, from 900 ℃, rise to 1200 ℃ again, be incubated 3.5 hours, finally cool to 200 ℃ with the furnace and come out of the stove below.

Second step, the formwork with ceramic core after after baking is carried out to secondary hardening, reinforcement process is as follows: silicate hydrolyzate liquid is slowly poured in the formwork after roasting from the cup of formwork, until flood to cup place, soak after 30 minutes, silicate hydrolyzate liquid is poured out, after natural drying and chemicosolidifying, it is to be cast that formwork gets final product etc. again.

Claims (1)

1. ceramic core secondary hardening method, is characterized in that, this method comprises the following steps:

The first step, formwork after dewaxing with ceramic core is carried out to after baking, roasting technique is as follows: with the heating rate of 4-5 per minute ℃, from normal temperature, rise to 900 ℃, insulation 1-2 hour, with the heating rate of 3-4 per minute ℃, from 900 ℃, rise to 1200 ℃ again, insulation 3-4 hour, finally cools to 200 ℃ with the furnace and comes out of the stove below;

Second step, the formwork with ceramic core after after baking is carried out to secondary hardening, reinforcement process is as follows: silicate hydrolyzate liquid is slowly poured in the formwork after roasting from the cup of formwork, until flood to cup place, soak after 20～40 minutes, silicate hydrolyzate liquid is poured out, after natural drying and chemicosolidifying, it is to be cast that formwork gets final product etc. again.