SU1470455A1 - Method of hot isostatic pressing of large cylindrical articles from powders - Google Patents

Abstract

This invention relates to the field of powder metallurgy, in particular, to the method of hot isostatic pressing of large-sized powder articles. The aim of the invention is to increase the equal density. The pressed billet is heated with the help of two inductors with a decrease in temperature from the ends to the center, and in diameter from the periphery to the center in the range of T _spec - (0.96-0.88) T _spec . The heated billet is subjected to hot isostatic pressing. The method provides an increase in the equal density: the density spread by the proposed method for titanium is 1.3%, nickel is 1.4%, high-speed steel is 1.7%, and according to the known method, the density spread is 4,4,7,1,9,1 % 6 tab.

Description

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The invention relates to powder metallurgy, in particular, to methods for hot isostatic pressing of large cylindrical powders.

 The aim of the invention is to increase the equal density.

The method is carried out as follows.

Compressed billet with a diameter of 200 mm and a height of 1000 mm is heated by two inductors: the first has 20 turns evenly distributed in height, the second has 2 turns; one at each end. The billet is heated unevenly with a decrease in temperature from the sintering temperature to 0.96-0.88 sintering temperature. The heated billet is subjected to isostatic pressing with a pressure of 120 Sha.

The distribution of heating temperature and density after hot isostatic. Extrusion to the middle of the billet in height and diameter for titanium, nickel and high-speed steel P18 are presented in Table 1-3.

Comparative data on the density distribution of the billets according to a known method of hot isostatic pressing with uniform heating of the billets of the same material are presented in Tables 4-6.

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Claims (1)

As follows from the presented data, the application of the proposed method provides a greater equal density than the known: the density variation of the proposed method for titanium is 37, nickel is 1.4%, high-speed steel is 1.7%, and by the known method is 4.4 7, one; 9.1%, respectively. Invention Formula The way of hot isostatic pressing of large cylinders 1470455 powders, which includes the molding of the workpiece, its heating and isostatic pressing, characterized in that, in order to improve the equal density, the workpiece is heated unevenly with decreasing temperature in height and diameter from the peripheral JO sections to the center from the sintering temperature of the product to 0, 96-0.88 temperature sintering. Temperature, heating and density distribution for the preparation of titanium powders, TG-TV Distribution of heating temperature and density for the preparation of powders of nickel H-1 Table 1 Table 2 514704556 Table3 The distribution of heating temperature and density for the billet of powders of high-speed steel P 18. Side surface 20 20 . 20 20 Workpiece axis 20 1000 / 97.9 990 / 98.2 980 / 99.6 970 / 99.0 990 / 98.2 980 / 99.0 970 / 99.6 960 / 99.2 980 / 99.4 970 / 99.5 960 / 99.6 950 / 99.6 970 / 99.6 960 / 99.6 950 / 99.6 940 / 99.6 960 / 99.6 950 / 99.6 940 / 99.6 930 / 99.5 960 / 98.5 950 / 98.8 940 / 99.3 930 / 99.3 920 / 99.3. Density distribution for billet of titanium powders. TG-TV when heating the entire workpiece to 980 ° C The density distribution for the billet of powders of nickel H-1 when heated the entire billet to. 980 / 99.4 970 / 99.5 960 / 99.6 950 / 99.6 970 / 99.6 960 / 99.6 950 / 99.6 940 / 99.6 960 / 99.6 950 / 99.6 940 / 99.6 930 / 99.5 Table4 Table3 Density distribution for a billet of high-speed steel powders P 18 heated throughout the volume to 990 ° С Size along the radius, mm Density,%, with the size of the butt height, mm 100 100 I 100 T 100 1 100 Side surface 20 20 20 20 Workpiece axis 20 Table 99.0 99.4 99.6 99.5 99.3 99.6 99.6 99.6 99.5 99.3 99.6 99.6 99.6 99.6 99.3