• LFP for Additive Manufacturing
  • 3D Printing of Large, Complex Metallic Glass Structures
  • Laser Metal Surface Polishing

LFP for Additive Manufacturing

 

Laser Foil Printing (LFP) for Additive Manufacturing

Tsai Project 1


INVESTIGATORS

Hai-Lung Tsai, Ming Leu, Chen Chen, Yiyu Shen, Yingqi Li, Chia-Hung Hung


FUNDING SOURCE
Department of Energy, UM Fast Track Program


PROJECT DESCRIPTION
The objective of the project is to develop a new additive manufacturing (AM) technology, called Laser Foil Printing (LFP), for fabricating three-dimensional (3D) metal parts. Instead of using metal powders as in most existing AM technologies, the new method uses metal foils as feed stock. The procedure consists of two alternating processes: foil welding by a high-power continuous-wave laser and foil cutting by a Q-switched ultraviolet laser. The foil welding process involves two sub-processes: laser spot welding and laser raster-scan welding. The reason for using two lasers is to achieve simultaneously the high-speed and high-precision manufacturing. The results on laser foil-welding and foil-cutting show that complete and strong welding bonds can be achieved with selected parameters, and that clean and no-burr/distortion cut of foil can be obtained. Several 3D AISI 1010 steel parts fabricated by the proposed AM technology are obtained, and the micro-hardness and tensile strength of the as-fabricated parts are both significantly greater than those of the original foil. The research has been extended to the fabrication of 3D complex metallic glass structures. This is the first time to be able to manufacture fully amorphous structures using the AM technology. The LFP can also be used for fabricating sensor-embedded parts and for outer space manufacturing under low gravity, vacuum, and low-temperature environments.

 

PUBLICATIONS 

  1. “Foil-Based Additive Manufacturing System and Method,” Hai-Lung Tsai, Chen Chen and Yiyu Shen, U.S./International Patent, filed on October 13, 2015. (United States application/PCT international application number PCT/US2015/055366).
  2. A foil-based additive manufacturing technology for metal parts,” Chen Chen, Yiyu Shen, and Hai-Lung Tsai, ASME Journal of Manufacturing Science and Engineering, published online August 24, 2016, also vol. 139, pp. 024501-1−024501-6, February 2017. 
  3. “Building Metallic Glass Structures on Crystalline Metal Substrates by Laser-Foil-Printing Additive Manufacturing,” Y. Li, Y. Shen, C. Chen, M.C. Leu, and H.L. Tsai, Journal of Materials Processing Technology, vol. 248, pp. 249-261, 2017.
  4. “3D Printing of Large, Complex Metallic Glass Structures,” Y. Shen, Y. Li, C. Chen, and H.L. Tsai, Materials and Design, vol. 117, pp. 213−222, 2017.

3D Printing of Large, Complex Metallic Glass Structures

 

3D Printing of Large, Complex Metallic Glass Structures 

Tsai Project 2

INVESTIGATORS
Hai-Lung Tsai, Ming Leu, Yiyu Shen, Yingqi Li, Chen Chen


FUNDING SOURCE
Department of Energy, UM Fast Track Funding Program


PROJECT DESCRIPTION
Metallic glasses (MGs) or amorphous alloys, although have superior mechanical properties their products are limited to simple geometries such as foils/plates or rods with thin section-thickness due to the requirement of high cooling rates. In this study, 3D, large dimensions of amorphous structures with complex geometry are manufactured by our newly developed Laser Foil Printing (LFP) technology. Zr-based (LM105, by Liquidmetal Technologies, Inc.) amorphous foils of 100 μm thickness are used as feed stock, and they are laser welded, layer-by-layer, to become 3D amorphous structures. Test results by the X-Ray diffraction (XRD), differential scanning calorimetry (DSC), and micro-hardness have confirmed that the printed structures at selected process parameters have achieved the same or better degree of amorphization as the raw foils. A mathematical model was developed to calculate the heating and cooling rates during structure manufacturing which helps the selection of process parameters. This study expands the MG products to 3D arbitrary geometries with large dimensions due to the inherited advantages of the LFP technology which would open a huge potential market. 


PUBLICATIONS

  1. "Method and system for manufacturing 3D, large, complex metallic glass structures," Hai-Lung Tsai, Yiyu Shen, Yingqi Li, Chen Chen, submitted to Technology Transfer & Economic Development and is being prepared by a patent attorney for submitting to patent application.
  2. "3D printing of large, complex metallic glass structures," Yiyu Shen, Yingqi Li, Chen Chen, and Hai-Lung Tsai, submitted to Materials and Design.
  3. “Laser welding of Zr-basedamorphous foils onto crystalline metal substrates,” Yingqi Li, Yiyu Shen, Chen Chen, Ming Leu, and Hai-Lung Tsai, submitted to Journal of Alloys and Compounds. 
  4. “Surface amorphisation of crystalized Zr-based bulk metallic glass by laser surface re-melting,” Yiyu Shen, Yingqi Li, Chen Chen, and Hai-Lung Tsai, submitted to Journal of Alloys and Compounds

Laser Metal Surface Polishing


Laser Metal Surface Polishing

 

Tsai Project 3

INVESTIGATORS
Hai-Lung Tsai, Chen Chen and Yiyu Shen.


FUNDING SOURCE
Department of Energy, UM Fast Track Funding Program


PROJECT DESCRIPTION
In any existing additive manufacturing technologies, the surface of as-fabricated metal parts are normally rough in a scale of 10s of microns. The objective of the project is to decrease the roughness down to a few10s of nano meters through both mathematical modeling and experiments. By using a laser, pulsed or continuous wave, the surface is melted allowing surface tension to act and smooth the top surface. The Marangoni surface tension force can be a function of temperature and some surface-active element. The fluid flow velocity at the surface can be used to estimate the time required to smooth a certain roughness of the surface which, in turn, will determine the laser parameters such as the laser power, beam spot size, scan speed, or pulse repetition rate. The modeling predictions will be validated by experiments and then will be used for parametric studies to find the best possible conditions for surface finish.  


PUBLICATIONS

  • A manuscript is in preparation.