Patents by Inventor Changlei Zhao

Changlei Zhao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7807216
    Abstract: A process to produce dense nanocrystalline composites such as ceramic bodies, coatings and multi-layered devices with uniform microstructure is disclosed. The invention utilizes sol-gel solutions to reduce agglomeration of nanocrystalline powders in the production of “green bodies” or intermediate products. This novel use of sol-gel solutions also reduces grain growth and porosity in products during sintering. In finished products, final grain sizes are typically less than 100 nm with densities of the final products approaching 99.5% of theoretical densities. In addition, sintering temperatures required are lower than those in conventional methods, typically less than 1,100° C. While FIG. 1 shows one application of this novel process, this invention has wide application in the manufacture of many other products, particularly for composite coatings and in the production of nanodevices.
    Type: Grant
    Filed: May 16, 2003
    Date of Patent: October 5, 2010
    Assignee: Nanyang Technological University
    Inventors: Weiguang Zhu, Zhihong Wang, Ooi Kiang Tan, Changlei Zhao
  • Publication number: 20050255239
    Abstract: A process to produce dense nanocrystalline composites such as ceramic bodies, coatings and multi-layered devices with uniform microstructure is disclosed. The invention utilizes sol-gel solutions to reduce agglomeration of nanocrystalline powders in the production of “green bodies” or intermediate products. This novel use of sol-gel solutions also reduces grain growth and porosity in products during sintering. In finished products, final grain sizes are typically less than 100 nm with densities of the final products approaching 99.5% of theoretical densities. In addition, sintering temperatures required are lower than those in conventional methods, typically less than 1,100° C. While FIG. 1 shows one application of this novel process, this invention has wide application in the manufacture of many other products, particularly for composite coatings and in the production of nanodevices.
    Type: Application
    Filed: May 16, 2003
    Publication date: November 17, 2005
    Inventors: Weiguang Zhu, Zhihong Wang, Ooi Tan, Changlei Zhao