Formations of structure of copper gazar of the difficult form

Purpose. At crystallization of gazar the question of interaction of several fronts of crystallization in volume of one form is important. Results of such interaction have to be reflected considerably in their structure and respectively in properties. As the main requirement to products from gazar - uniformity of steam structure, the purpose of work is studying of regularities of formation of structure of gazar at two axial the located refrigerators in one form. Technique. As material for production of samples of gazar M0 brand copper served. The nozzles cooled by water acted as refrigerators, nearby with each other in one form. Metal melted in the autoclave with the set gas pressure, and then was poured in a form with a pressure, necessary for process. Applied research methods - optical microscopy, measurement of porosity by means of the personal computer. Results. It is established that in meeting places of fronts of crystallization zones of a time of merge which sizes considerably exceed the sizes of a time in the gaseutectic colonies are formed. For stable course of process, it is necessary to provide the minimum movement of fusion, a stable temperature gradient, constancy or stability of change in crystallization pressure time; free leaving of fusion and hydrogen from the front of crystallization, increase of working pressure to P ? 1,3 - 1,4 MPa. Scientific novelty. Differences in structure of castings at its formation depending on orientation of refrigerators are revealed. Ways of elimination of a defective zone in castings are considered. Practical importance. Use of the received results will allow to operate effectively porous structure of products with two axial fronts of crystallization, to liquidate possibility of formation of a defective zone, considerably to increase quality of cast products.