SU1028413A1 - Cold hardenable mixture for making moulds and cores - Google Patents

Abstract

A COOLING MIXTURE FOR THE MANUFACTURE OF CASTING FORMS AND RODS, including refractory silica-based filler, aluminum phosphate binder and hardener, f from. In order to improve the mixture of castings from castings and to improve the cleanliness of the surface of castings from copper-based alloys, it contains triethanolamine as a hardener in the following ratio of ingredients, May. %: Alumochromophosphate bond3-5 Triethanolamine 0,2-O, 5 Refractory silica-based filler Else.

Description

0 00 iCiii The invention of the foundry industry, in particular the manufacture of drinking forms of cold-hardening mixtures (Yata). Known XTG for the manufacture of casting molds and rods, containing a silica-based refractory filler, an aluminum-chromophosphate binder, a urine formaldehyde resin, orthophosphoric acid, and magnesium oxide. However, the presence of urea-formaldehyde resin in the composition of this chemical and chemical complex leads to a deterioration of sanitary and hygienic working conditions at the core and flooded areas. The gas-permeability of a given CTS can cause the formation of gas defects in castings. Closest to the invention to the technical essence and the achieved result is the CTS for the manufacture of casting molds and cores, containing 4 weight. % alumochromophosphate bond, 5 wt. % hardener in the form of finely ground manganese ore (pyrolusite or iron ore concentrate and the rest is a refractory filler based on silica 2 3. However, despite the high physicomechanical properties of this mixture, it is used mainly for iron-based alloys, as when using it for copper-based alloys did not ensure the ease of knockout of the mixture from castings. In addition, the use of polyvalent metal oxides in hardening in specified quantities in the preparation of castings from alloys to honey The basis of the invention is to improve the blendability of the mixture of castings and to improve the purity of the direction of copper-based alloy grades. To achieve this goal, a cold-hardening mixture for the manufacture of foundry molds and cores, including refractory filler A silica, alumochromophosphate bond and hardener, contains triethanolamine as a hardener with the following ratio of ingredients, May. %: Alumochromophosphate bond3-5 Triethanolamine 0.2-0.5 Refractory silica-based filler Others When there is less than 3% bonded content in sk, the mixture has insufficient survivability and high frittability, while its content is more than 5%, and Ceceg increased adhesion to the model. m and pins. With the introduction of the driver, less than O, 2% or more than 0.5%, respectively, very slow or very fast curing of the mixture. The proposed blend is prepared as follows. The dry refractory granular aggregate, nsrimer quartz sand, is mixed with the calculated amount of bond for 3 minutes, after which the triethanolamine wrench is introduced and the entire mixture is mixed for 2 minutes. Known mixing equipment from foundries is used to mix the components. The manufacture of molds and cores from this mixture is carried out by nyieM its compaction in the flasks and core boxes by any known method. (manually, by vibration, etc.). Shapes and rods harden at room temperature. When using the proposed method, it is possible to obtain molds and cores that do not possess tassicity, have high strength properties, low ostachemost and fCOCTb gugutver, high gas permeability v good knockability after pouring. In tab. Table 1 lists the compositions of the proposed mixtures 1–3 and the mixtures that were known from | 4. The results of tests of mixtures 14 are given in Table. 2. From the data table. 2 it follows that the thread 400C, the underlying mixture, starting to reduce the residual strength is especially noticeable and substantial in the temperature range of 60 ° –9 ° C. This means that the squeeze offered provides an improved knockout of rods from castings made of copper alloy alloys. In comparison with the prototype, the properties of the proposed mixture are tested on castings of the third group of E-type copper-based alloy mixtures; P caoF 1 m aoU2 j in 4f mixture, type J-J, used as an hardener a number of transition polyvalent metals, such as nM,

forming light-plate eutectics and special structures of education. In the mixture 2 according to the invention, the curing agent is triethanolamine, which also, ilk and AHFS, is a material that reduces burns in the castings. The surface of the castings obtained in the mixture according to

to the prototype, 50% of it was used as a stick, and from the proposed mixture - not 7-10%, and only in other countries. Consequently, the proposed mixture provides an improved surface cleanliness of castings from copper-based alloys.

Table 1

Quartz ne

the juice

Alumochromophosphate bond with a density of 1.56-1.60 g / / cm Triethanolamine

density

1.12

Iron ore concentrate or pyrolusite

Sapability

OD5-O.2O 0.15-0.20 0.03-O, 1O

0.2-0.3

Gas storage, unit 260-280

26О-280

95.7 94,591. About

0.3O, 5

table 2

260-280

Continuation of table 2

Claims (1)

COLD-MIXING MIXTURE FOR THE PRODUCTION OF CASTING FORMS AND RODS, including a refractory filler based on silica, alu! a mohromophosphate binder and hardener * · characterized in that, in order to improve the knockout of the mixture from castings and to improve the surface cleanliness of castings from copper-based alloys, it contains nolamine as the hardener in the following ratio of ingredients, May. %: Alumochromophosphate binder T Riethanolamine Silica Refractory Filler 3-5 0.2-0.5 I 1 1028413