多层喷射沉积制备大尺寸耐热铝合金管坯的研究

Preparation of Heat-Resistant Aluminum Alloy Pipe Blanks with Large Dimensions by Multi-Layer Spray Deposition

采用多层喷射沉积工艺制备出了尺寸为Φ6 30mm× 2 5 0mm× 80 0mm且质量较好的FVS0 812耐热铝合金管坯 ,通过挤压获得了性能优良的大直径管材 ,并对管坯和挤压后管材的力学性能和微观结构进行了检测和分析。分析结果表明 ,多层喷射沉积制坯过程中 ,熔滴在沉积面的冷却速度约 3.2× 10 4 K·s- 1～10 6 K·s- 1,熔滴凝固后在沉积坯中形成微细晶粒结构 (2 0 0nm～ 5 0 0nm)和弥散分布的纳米析出相Al12 (Fe ,V) 3Si(2 0nm～ 6 0nm) ,使得沉积坯挤压致密后具有优异的性能。

Pipe blanks of FVS0812 alloy with dimension of Φ 630 mm×380 mm×800 mm were prepared by multi layer spray deposition (MLSD)technology. Alloy pipes with high performance were produced by extrusion. The characteristics of as processed pipes' mechanical properties and microstructure were analyzed. The results show that with molten droplets cooling down at average cooling rate of 3.2×10 4 K·s -1 ～10 6 K·s -1 ,grains with size between 200 nm to 500 nm and spherical phase Al 12 (Fe,V) 3Si with size between 20 nm to 60 nm were shown in the blanks, which made the pipe blanks show high performance after extrusion.