Grain size control in refractory carbides using hot plastic straining and recrystallization annealing

Abstract

Abstract A METHOD OF CONTROLLING THE GRAIN SIZE OF A REFRACTORY METAL CARBIDE BODY COMPRISING RECRYSTALLIZED CRYSTALLITES OF THE CARBIDE OF A METAL OF GROUPS IV-B AND V-B OF THE PERIODIC TABLE WHEREIN A BODY OF ONE OR MORE REFRACTORY METAL CARBIDES SELECTED FROM THE CARBIDES OF THE GROUP CONSISTING OF TI, ZR, HF, V, NB, AND TA IS AS AN ELEVATED TEMPERATURE BETWEEN A POINT OF FROM ABOUT ONEHALF OF THE MELTING POINT OF THE CARBIDE TO A POINT JUST BELOW THE SOLIDUS TEMPERATURE; AND WHILE HOLDING THE TEMPERATURE SUBSTANTIALLY CONSTANT SUBJECTING THE CARBIDE TO A MECHANICAL STRAIN IN AN AMOUNT EQUAL TO AT LEAST THE CRITICAL STRAIN NECESSARY THE STRESS AND ANNEALING THE STRAINED BODY AT AN ELEVATED TEMPERATURE IN THE RANGE OF FROM THE STRAINING TEMPERATURE BUT NOT EXCEEDING THE SOLIDUS TEMPERATURE (THE TEMPERATURE AT WHICH A LIQUID PHASE IS FORMED) FOR A PERIOD OF TIME SUFFICIENT TO CAUSE COMPLETE RECRYSTALLIZATION OF THE CARBIDE, WHEREBY THE DESIRED RECRYTALLIZED GRAIN SIZE VARIES INVERSELY WITH THE AMOUNT OF STRAIN APPLIED TO THE CARBIDE.

Inventors

• 👤 Joseph M Tobin
• 👤 Leonard R Fleischer

Bibliographic Details