Fabrication and High-Temperature Compressive Behavior of Unique Multi-Sheet Stacked Block Ni–Cr–Al Metallic Foam

The effects of hydrogen on the microstructure and hot deformation behavior of Ti-6Al-4V alloy were studied, and the differences of microstructure and high temperature compressive behavior between the specimens hydrogenised various time at 700 oC and with the same hydrogen contents were analyzed. The results showed that the addition of hydrogen decreases the deformation resistance of Ti-6Al-4V alloy at high temperature. The flow stresses of specimens with the same hydrogen content declined as the prolongation of hydrogenating time. The microstructure observation indicated that stick-type microstructure was obtained in Ti-6Al-4V alloy annealed at 700 oC for 2 hours. Hydrogenation at 700 oC for 2 hours resulted in fine α plate in β transformed microstructure. When the hydrogenation time was prolonged to 6 hours, the volume fraction of newly-formed α plates increased and the prior α plates became coarser.

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Effect of Yttrium on Microstructural Evolution and High Temperature Compressive Behavior of Ti–Ni–Hf High Temperature Shape Memory Alloys

Science of Advanced Materials ◽

10.1166/sam.2017.2940 ◽

2017 ◽

Vol 9 (6) ◽

pp. 1028-1031

Author(s):

Jeoung Han Kim ◽

Sung Young

Keyword(s):

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

Microstructural Evolution ◽

Compressive Behavior

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Preparation of Ti-Al Intermetallics by Aluminum Melt Infiltration-Diffusion Annealing Technique

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.367 ◽

2007 ◽

Vol 561-565 ◽

pp. 367-370

Author(s):

Li Qing Chen ◽

Ji Jie Wang ◽

Lin Chen

Keyword(s):

High Temperature ◽

Reaction Mechanism ◽

Melting Point ◽

Elevated Temperatures ◽

Diffusion Annealing ◽

Compressive Behavior ◽

Porous Ti ◽

Temperature Diffusion ◽

Melt Infiltration ◽

Long Time

A novel process, of melt infiltration combined with diffusion annealing technique, was developed to prepare Ti-Al intermetallics at temperature lower than ingot melting point. In this process, a porous Ti preform was firstly fabricated and the Al melt was reheated to temperature slightly higher than Al melting point to infiltrate the porous Ti preform by capillary force spontaneously. After long-time high-temperature diffusion annealing, Ti-Al intermetallic compound can be finally synthesized from the bulk Tip+melt Al via diffusion. As example, Ti-46Al intermetallics has been fabricated, and the microstructures and the phases of the as-synthesized intermetallics were characterized by XRD and SEM. The compressive behavior of the as-synthesized Ti-Al at elevated temperatures has been studied and the reaction mechanism involved in the process finally analyzed.

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