Effects of Composition and Post Heat Treatment on Shape Memory Characteristics and Mechanical Properties for Laser Direct Deposited Nitinol

PMMA, PC, and PEEK are thermoplastic polymers that possess favorable properties for biomedical applications. These polymers have been used in fields of maxillo-facial, orthopedic, intraocular surgery, and bio-implant, due to their excellent mechanical properties, osteoinductive potential, and antimicrobial capabilities. In this study, the effect of heat treatment on the mechanical properties of 3D printed polymers was characterized. By modifying printing temperature and post heat treatment process, the mechanical properties were specifically tailored for different applications, correlating with the properties of the implants that are commonly made using molding processes.

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Effects of Post Heat Treatment on the Mechanical Properties of Cold-Rolled Ti/Cu Clad Sheet

Metals ◽

10.3390/met10121672 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1672

Author(s):

Chang-Suk Youn ◽

Dong-Geun Lee

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Rolling Process ◽

Post Treatment ◽

Post Heat Treatment ◽

Clad Sheet ◽

Heat Treated ◽

Bonding Properties ◽

High Elongation ◽

Cold Rolled

Titanium and titanium alloys have excellent corrosion and heat resistance, but weak electric and thermal conductivity. The weak conductivity of titanium can be overcome by cladding with copper, which has high conductivity. Although titanium is expensive, it is selected as a material suitable for applications requiring corrosion resistance such as in heat exchangers. This study was to investigate the effect of post heat treatment on the mechanical properties of the Ti/Cu cold-rolled clad plate by using the interfacial diffusion bonding. A titanium clad by cold rolling should be heat-treated after the rolling process to improve the bonding properties through the diffusion of metals and removal of residual stress due to work hardening, despite the easy formation of intermetallic compounds of Ti and Cu. As a result post-treatment, the elongation was improved by more than two times from 21% to max. 53% by the Ti-Cu interface diffusion phenomenon and the average tensile strength of the 450 °C heat-treated specimens was 353 MPa. By securing high elongation while maintaining excellent tensile and yield strength through post-treatment, the formability of Ti-Cu clad plate can be greatly improved.

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Impact of Morphology and Microstructure on the Mechanical Properties of Ge-As-Pb-Se Glass Ceramics

Applied Sciences ◽

10.3390/app10082836 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2836 ◽

Cited By ~ 1

Author(s):

Rashi Sharma ◽

Rebecca Welch ◽

Myungkoo Kang ◽

Claudia Goncalves ◽

Cesar Blanco ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Vickers Hardness ◽

Glass Ceramic ◽

Volume Fraction ◽

Glass Ceramics ◽

Post Heat Treatment ◽

Base Glass ◽

Parent Glass ◽

Crystal Phases

The impact of base glass morphology and post heat-treatment protocol on the mechanical properties (Vickers hardness and Young’s modulus) of a multi-component glass-ceramic was examined. Two parent chalcogenide glasses with identical composition but varying morphology (homogeneous and phase separated) were evaluated for their mechanical properties following identical thermal processing to induce crystallization. The nucleation and growth rates of the starting materials were compared for the two glasses, and the resulting crystal phases and phase fractions formed through heat treatment were quantified and related to measured mechanical properties of the glass ceramics. The presence of a Pb-rich amorphous phase with a higher crystal formation tendency in the phase-separated parent glass significantly impacted the volume fraction of the crystal phases formed after heat-treatment. Pb-rich cubic crystal phases were found to be dominant in the resulting glass ceramic, yielding a minor enhancement of the material’s mechanical properties. This was found to be less than a more moderate enhancement of mechanical properties due to the formation of the dominant needle-like As2Se3 crystallites resulting from heat treatment of the homogeneous, commercially melted parent glass. The greater enhancement of both Vickers hardness and modulus in this glass ceramic attributable to the high-volume fraction of anisotropic As2Se3 crystallites in the post heat-treated commercial melt highlights the important role base glass morphology can play on post heat-treatment microstructure.

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