Controlled rejuvenation of amorphous metals with thermal processing

Area of Science:

• Materials Science
• Condensed Matter Physics

Background:

• Amorphous metals often exhibit brittle fracture, limiting their applications.
• Rejuvenation, or configurational excitation, offers a promising route to enhance deformability.
• Controlling rejuvenation is key to unlocking the potential of amorphous metals.

Purpose of the Study:

• To propose and validate a method for controlling the level of rejuvenation in amorphous materials.
• To elucidate the critical conditions for achieving controlled rejuvenation through thermal processing.
• To demonstrate experimental control over rejuvenation in a specific bulk metallic glass.

Main Methods:

• Utilizing molecular dynamics simulations to model annealing and quenching processes.
• Systematic thermal processing to induce and control configurational excitation.
• Experimental verification using Zr(55)Al(10)Ni(5)Cu(30) bulk metallic glass.

Main Results:

• A novel thermal processing method is presented to control rejuvenation levels.
• Feasibility conditions for controlled rejuvenation were clarified via simulations.
• Successful experimental demonstration of rejuvenation level control in a bulk metallic glass.

Conclusions:

• The proposed thermal treatment, involving heating above 1.1Tg followed by a faster quench, enables controlled rejuvenation.
• This method allows for post-casting modification of amorphous material properties.
• Transient laser heating offers spatial control and processing flexibility for rejuvenation.