Figure 8: Microstructure of the spray formed and hot pressed alloy, a — longitudinal microsection, b — transverse 
microsection, c — longitudinal microsection at higher magnification 
The influence of the betatization temperature on the microstructure is shown in Fig.9. The 
specimens were quenched in oil from the betatization region ( 950°C ). Fig.9a shows the 
known microstructure of the spray formed and hot pressed state. By the betatization at 700 
and 800°C ( Fig.9b and 9c ) the y, — phase is dissolved and the banded grains of the matrix 
consist now of ordered bcc ; — phase as shown by the X — ray diffraction pattern in Fig.11. 
Small x — precipitations exist in the f, - grains ( Fig.10a and 10b ). The betatization at 850°C 
or higher temperatures produces also the disolution of the y, — phase. Additional the shape of 
the matrix grains is changed. After the betatization polygonal B, — grains exist in the 
microstructure ( Fig.9d and 9e ). In the grains some small x — particles are present ( Fig.10 ¢). 
265