| 摘要 |
<p>super-alloy powder of av. particle size 100 mu, (pref. 10-60 mu) is heated at a high temp. to cause sintering and recrystallisation forming a billet with a grain size 2.54 mu and O2-content 100ppm. The billet is heated to a temp. above half the value of the alloys absolute fusion temp. but below the initial fusion point, and extruded. Spec. the preheating is to just below the recrystallisation temp. so that the adiabatic heating caused by extrusion is sufficient to increase the alloy temp. into the recrystallisation range. Final heat treatment is effected to produce grain growth to 2.54 mu. Alloy is used in aviation, space research etc. where strength at high temp. e.g. ca 760 degrees C is important. Complex shapes are produced to fine tolerances without the need for machining.</p> |
