Abstract: A novel mixed solid-liquid casting technology was utilized to prepare elevated temperature aluminum alloy (8009). The results show that, comparing with conventional casting processing and stirring casting process,this process can effectively refine the grains and precipitated Al13Fe4 phase particles and can obviously improve the room temperature or high temperature mechanical properties. Better extrudability,abrasive resistance at room temperature and high temperature can also be obtained by this process. When mass ratio of the alloy powder to the melt is up to 1,the mean size of the Al13Fe4 particles in the alloy samples can be controlled under 30μm; its mechanical properties at room temperature is σb=210MPa,σ0.2=190MPa,δ=4%; at 473K,σb=150 MPa,σ0.2=130MPa,δ=5%;at 573K,σb=110MPa,σ0.2=90MPa,δ=6%.
Mixed solid-liquid casting processing of Al-8.7Fe-1.6V-1.3Si elevated temperature alloy
Abstract:
A novel mixed solid-liquid casting technology was utilized to prepare elevated temperature aluminum alloy (8009) . The results show that, comparing with conventional casting processing and stirring casting process, this process can effectively refine the grains and precipitated Al 13Fe 4 phase particles and can obviously improve the room temperature or high temperature mechanical properties. Better extrudability, abrasive resistance at room temperature and high temperature can also be obtained by this process. When mass ratio of the alloy powder to the melt is up to 1, the mean size of the Al 13Fe 4 particles in the alloy samples can be controlled under 30?μm; its mechanical properties at room temperature is σ b=210?MPa, σ 0.2=190?MPa, δ=4%; at 473?K, σ b=150?MPa, σ 0.2=130?MPa, δ=5%; at 573?K, σ b=110?MPa, σ 0.2=90?MPa, δ=6%.
Table 1 Mechanical properties of as-prepared 8009 alloy by different processes
Process
Room temperature
473?K
573?K
σb /MPa
σ0.2 /MPa
δ/%
σb /MPa
σ0.2 /MPa
δ/%
σb /MPa
σ0.2 /MPa
δ/%
Conventional casting process
30~40
30~40
0
Semi-solid casting process
96
86
0.4
Solid-liquid mixed casting process
212
190
4
150
130
5
110
90
6
图2 粉末加入对固液混合铸造合金室温力学性能的影响
Fig.2 Influences of added powder on mechanical properties of alloys at room temperature
(a) —Influence of addition amount of powder; (b) —Influence of particle size of powder
表2 固液混合铸造与粉末冶金坯单位面积挤压抗力的比较 (MPa)
Table 2 Comparison of resistances to extruding deformation per unit area between mixed solid-liquid casting samples and powders metallurgy samples (MPa)