Effects of Heat Treatment and Extrusion on Microstructure and Properties of A390 Alloy Hollow Billet Fabricated via DC Casting

Purpose – The purpose of this paper is to study the effect of feeding scheme on melt flow and temperature field during the steady-state of level-pour direct-chill (DC) casting of A390 alloy hollow billet and optimize the design of feeding scheme. Design/methodology/approach – Melt flow and temperature field are investigated by numerical simulation, which is based on a three-dimensional mathematical model and well verified by experiments. Findings – The numerical results reveal that both melt flow and temperature field are obviously affected by the feeding scheme. The homogeneity of melt flow and temperature field in hollow billet with the feeding scheme of modified four inlets are better than the other feeding schemes. Experimental results show that crack can be eliminated by increasing the number of feeding inlets. The primary Si size appears unaffected while the distribution of primary Si particles is highly affected by the change of feeding scheme. Only with the feeding scheme of modified four inlets can fine and uniformly distributed primary Si particles be achieved. Practical implications – The paper includes implications for the design of feeding scheme in level-pour DC casting of hollow billet for practical use. Originality/value – This paper develops different feeding schemes for level-pour DC casting of hollow billet and optimizes the design of feeding scheme.

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Microstructure and properties of Ni-Co-Mn-Al magnetic shape memory alloy prepared by direct laser deposition and heat treatment

Optics & Laser Technology ◽

10.1016/j.optlastec.2021.107119 ◽

2021 ◽

Vol 141 ◽

pp. 107119

Author(s):

Wuming Jia ◽

Suiyuan Chen ◽

Luting Wang ◽

Fanmin Shang ◽

Xinru Sun ◽

...

Keyword(s):

Heat Treatment ◽

Shape Memory Alloy ◽

Shape Memory ◽

Laser Deposition ◽

Magnetic Shape Memory ◽

Direct Laser Deposition ◽

Microstructure And Properties ◽

Magnetic Shape Memory Alloy ◽

Direct Laser

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Effect of Cooling Rate on Microstructure and Properties of Heat-Treated Fe3Al Intermetallics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.3891 ◽

2011 ◽

Vol 189-193 ◽

pp. 3891-3894

Author(s):

Ya Min Li ◽

Hong Jun Liu ◽

Yuan Hao

Keyword(s):

Heat Treatment ◽

Cooling Rate ◽

Lattice Distortion ◽

Annealing Furnace ◽

Microstructure And Properties ◽

Homogenizing Annealing ◽

Heat Treated ◽

Mixed Fracture ◽

Sand Mould ◽

The Impact

The casting Fe3Al intermetallics were solidified in sodium silicate sand mould and permanent mould respectively to get different cooling rates. After heat treatment (1000°С/15 h homogenizing annealing + furnace cooling followed by 600°С/1 h tempering + oil quenching), the microstructure and properties of Fe3Al intermetallics were investigated. The results show that the heat-treated Fe3Al intermetallics at higher cooling rate has finer grained microstructure than lower cooling rate, and the lattice distortion increases due to the higher solid solubility of the elements Cr and B at higher cooling rate. The tensile strength and hardness of the Fe3Al intermetallics at higher cooling rate are slightly higher also. However, the impact power of intermetallics at higher cooling rate is 67.5% higher than that at lower cooling rate, and the impact fracture mode is also transformed from intercrystalline fracture at lower cooling rate to intercrystallin+transcrystalline mixed fracture at higher cooling rate.

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Effect of Heat Treatment on Microstructure and Properties of Cu-3Ti-1Al Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.749.282 ◽

2013 ◽

Vol 749 ◽

pp. 282-286

Author(s):

Xian Hui Wang ◽

Xiao Chun Sun ◽

Xiao Hong Yang ◽

Shu Hua Liang

Keyword(s):

Heat Treatment ◽

Solid Solution ◽

Electrical Conductivity ◽

Electron Microscope ◽

Treatment Process ◽

Intermetallic Phase ◽

Strengthening Effect ◽

Microstructure And Properties ◽

Optimal Heat Treatment ◽

Transmission Electron

The effect of heat treatment on the microstructure and properties of Cu-3Ti-1Al alloy was investigated. The microstructure was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), and the hardness and electrical conductivity were tested as well. The results showed that the hardness and electrical conductivity of Cu-3Ti-1Al alloy increased significantly after solid solution and ageing treatment. The strengthening effect of Cu-3Ti-1Al alloy was attributed to the formation of intermetallic phase such as Ti3Al and fine precipitates of coherent β-Cu4Ti. With increase of the aging time and the temperature, the precipitates became coarse and incoherent with Cu matrix, and the discontinuous precipitate β started to grow from grain boundaries toward grain interior, which decreased hardness. As the formation of Ti3Al, β-Cu3Ti and β-Cu4Ti phase can efficiently reduce Ti concentration in Cu matrix. The electrical conductivity of Cu-3Ti-1Al alloy increases. In the range of experiments, the optimal heat treatment process for Cu-3Ti-1Al alloy is solid solution at 850°C for 4h and ageing 500°C for 2h, and the hardness and electrical conductivity are 227HV and 12.3%IACS, respectively.

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