Expert in Surface Engineering, Diamond like hard coating, material science, Medical device, hard disk
In the past 15 years, experts has been working on the characterization of the surface morphology, microstructure, crystalline structure, mechanical properties, including internal stress, microhardness, Young’s modulus, adhesion, wear resistance, of metal bulk materials and hard coatings and thin films, including TiN, TiAlN, TiSiN, TiCrN, CrN, diamond like carbon (DLC), metal containing diamond like carbon, TiN/Ti multilayers, using atomic force microscopy (AFM), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), FTIR, Raman, surface profilometer, microhardness indenter, nanoindenter, Rockwell adhesion tester, scratch adhesion tester, and Pin-on-disk tribometer.
Expert has been working on the development of inorganic coatings (diamond like carbon based nanocomposite coatings, Ag based coatings, and titanium oxide (TiO2) coatings) for medical devices, such as implants, stents, pacemarkers, artificial heart, to improve their hemocompatibility, biocompatibility, antibacterial, antimicrobial, and corrosion resistance.
One of the expert’s goals is to apply the developed hard coatings in the cutting tools. Expert has extensive experience in the design and selection of base materials and the surface modification techniques and surface coatings for cutting tools, dental instruments, and surgical instruments to improve their wear resistance, corrosion resistance, and oxidization resistance. Expert has applied a surface modification technology to WC cutting tools, dental instruments, drill bits, which improve their lifetime by >2 times, >100 times, and >10 times, respectively.
Expert has been actively involved in the area of stainless steels, including austenitic, ferritic, martensitic, dual-phase, and precipitation hardening (PH) stainless steels. Expert has assisted many customers with steel selection, heat treatment, and failure analysis of various stainless steels. Some recent work involved heat treatment of 440-XH, 440-C, 420, 17-4, 13-8, and the selection of stainless steel for dental and surgical instruments, including dental scalers and drill bits, and corrosion resistance of 440-XH, 440-C, and 316L.
Expert has extensive experience and knowledge in the selection, deposition process optimizing, and characterization of thin films and coatings. The range of thin films include, diamond like carbon (DLC), doped diamond like carbon, carbon nitride, TiN, ZrN, TiAlN, TiSiN, CrN, TiCN, Ag, Cu, WC, MgO, TiO2, and ZrO2. He has designed and developed coatings for meeting specific demands such as wear, corrosion resistance, and biocompatibility, antimicrobial, antibacterial, and hemocompatibility.
Expert has direct industry experience in the surface preparation and cleaning for thin films and coatings deposition to prevent the delamination of the coatings from the substrates. Expert has developed a surface cleaning process for the deposition of TiN based hard coatings on dental instruments, which reduced the production reject rate from >30% to <5%.
Expert has direct experience in the corrosion testing, corrosion protection by surface coatings, and providing advice on the proper choice of materials and surface coatings. Export has strong background and experience in the corrosion (alkaline corrosion, chlorine corrosion, and autoclave corrosion, biological corrosion) prevention of steels, especially stainless steels, by applying chemical inert coatings, such as diamond like carbon coatings, TiN, TiSiN, and TiO2, and sacrificial coatings, such as Al, Zn, AlNi, and AlZn coatings.
Expert has direct experience with the heat treatment and superelastic behavior of TiNi shape memory alloy.
Expert has had many years of experience in the metallurgical engineering. He was an associate professor in the Department of Metal Materials and Heat Treatment. He taught courses of “Physical Metallurgy” and “Phase Transformation in Solid State” for graduate and undergraduate students in a top 10 university in China. He developed a new alloy steel for plastic die and mould, which are commercial available in China. He has extensive knowledge of the different heat treating procedures, including annealing, austenitizing, quenching, tempering, solution treating, precipitation hardening, and surface alloying, from a particular steel of alloy. Expert has recommended the optimum heat treating procedures for obtaining the properties required for particular applications. Expert has involved in the corrosion and breakage failure analysis of dental instruments (scalers and ultrasonic dental instruments) to determine source modes and causes, and to provide solutions for the failure of dental instruments.
Expert has more than 15 years of academic and industry experience in developing of advanced coating materials to improve the surface hardness, wear resistance, abrasion resistance, corrosion resistance, and compatibility of materials for dental instruments, surgical instruments, medical devices, hard disk drives.
He recommended a deposition process for TiAlN coatings using cathodic arc deposition technology to improve the service life of hot work dies.He has recommended the optimum heat treating procedures for steels and alloys for obtaining the properties required for particular applications. He has recommended the base material, and surface modification and coating deposition techniques and processes for cutting tools and cutting dental and surgical instruments to improve their wear and corrosion resistance.
Expert may consult nationally and internationally, and is also local to the following cities: Minneapolis, Minnesota - Saint Paul, Minnesota - Rochester, Minnesota - Burnsville, Minnesota - Saint Cloud, Minnesota - Eden Prairie, Minnesota - Minnetonka, Minnesota - Eau Claire, Wisconsin
|Year: 1997||Degree: PhD||Subject: Materials Science and engineering||Institution: Huazhong University of Science and Technology|
|Year: 1994||Degree: Master||Subject: Materials Science and engineering||Institution: University of Science and Technology|
|Year: 1991||Degree: BS||Subject: Metal Material and Heat Treatment||Institution: University of Science and Technology|
|Years: 2012 to Present||Employer: Undisclosed||Title: Staff Engineer||Department: Advanced Transducer Development||Responsibilities: He is responsible for developing reliability testing metrology and improving reliability of new HAMR magnetic recording head by developing new thin film materials, including gold alloying, interface adhesion improvement, HOC, gas barrier coating, and corrosion prevention.|
|Years: 2010 to 2012||Employer: Medtronic Inc.||Title: Principle Engineer||Department: Feedthrough development||Responsibilities: He is responsible for developing new hermetic feedthrough for medical devices and improving reliability for implantable medical devices.|
|Years: 2006 to 2010||Employer: American Eagle Instruments, Inc.||Title: Materials Scientist/Principle investigator||Department:||Responsibilities: He is responsible for developing new materials and new surface modification technologies to improving the service life of dental instruments, surgical instruments, and medical implants.
|Years: 2005 to 2006||Employer: University of Texas at Arlington||Title: Post doctoral research associate||Department: Materials Science and Engineering||Responsibilities: Works with carbon based nanocomposite hard coatings (diamonds).|
|Years: 2003 to 2005||Employer: Carnegie Mellon University||Title: Post doctoral research associate||Department: Physics||Responsibilities: He did research work in the synthesis of Fe, Fe3O4, Fe/Pt core/shell nanoparticles with a size of 3-10 nm by high temperature chemical methods, and the characterization of the Fe and Co nanoparticles and arrays by transmission electron microscopy (TEM).|
|Years: 2001 to 2003||Employer: Chemnitz University of Technology, Germany||Title: Research Scientist||Department: Physics||Responsibilities: His work was mainly focused on the development and optimization of deposition process of oxide coatings (MgO, and TiO2) by using pulsed magnetron sputtering.|
|Years: 1999 to 2001||Employer: Nanyang Technological University, Singapore||Title: Research Fellow||Department: Electric and Electronic Engineering||Responsibilities: His work was mainly focused on the development and optimization of deposition process for hard coatings, including diamond like carbon, nanocomposite films, Cu, TiN, TaN, ZrN, and (Ti,Al)N coatings, using filtered cathodic arc.|
|Years: 1997 to 2001||Employer: Huazhong University of Science and Technology, P.R. China||Title: Associate professor, vice director||Department: Materials Science and Engineering||Responsibilities: He was an associate professor and a vice director of the Materials Science and Engineering department.He did research work in the developing biomedical coatings for implants to improve their biocompatibility, corrosion resistance, and wear resistance using PECVD technique.|
|Years: 2008 to Present||Agency: TATRC, U.S. Army Medical Research & Materiel Command||Role: Materials Scientist||Description: He is in charge of the TATRC projects to develop an advanced surface engineering technology, process, and coating materials for surgical tools, implants, and medical devices to improve their wear resistance, corrosion resistance, biocompatibility, hemocompatibility, and antibacterial properties.|
|Years: 2006 to 2008||Agency: Army Research Laboratories||Role: Materials Scientist||Description: He was doing research work in the development and characterization of wear, corrosion, and erosion resistant coatings for parts and components used in army and air force.|
|Years||Country / Region||Summary|
|Years: 1997 to 1999||Country / Region: P.R. China||Summary: He was an associate professor and a vice director of the Materials Science and Engineering department. He also taught cause of “Solid State Phase Transformation” for graduate students, and did research work in the (1) development of a plasma assisted pulsed laser ablation technique for the deposition of novel diamond like carbon based coatings and carbon nitride coatings; (2) optimization of the deposition processes and characterization of diamond like carbon films deposited by radio frequency PECVD, pulsed laser ablation, and cathodic arc; (3) characterization of the biocompatibility of carbon based coatings; and the (4) application of the (Ti, Al)N coatings for hot work Die and Mould. He also worked on the development of a new Pins Steel of Plastic Dies (65MnV) and a Cold Work Tool steel.|
|Years: 1999 to 2001||Country / Region: Singapore||Summary: His work was mainly focused on the (1) development and optimization of deposition process for hard coatings, including Cu, TiN, TaN, ZrN, and (Ti,Al)N coatings and diamond like carbon based nanocomposite films, i.e. tetrahedral amorphous carbon (ta-C films), carbon nitride films, and metal (W, Fe, Ni, Mo, Cu, V, Al, and Ti) containing tetrahedral carbon films (ta-C: Me), by off-plane double-bend filtered cathodic vacuum arc (FCVA) technique; (2) characterization of the hardness, Young’s modulus, internal stress, wear resistance, surface energy, surface morphology, crystalline structure, composition, and bonding structures of the deposited coatings using nanoindenter, microhardness indenter, substrate curvature method, pin-on-disc, micro-drop method, atomic force microscopy (AFM), SEM, XRD, XPS, Raman, and FTIR, respectively.|
|Years: 2001 to 2003||Country / Region: Germany||Summary: His work was mainly focused on the (1) development and optimization of deposition process of oxide coatings (MgO, and TiO2).|
|Associations / Societies|
|Member of the AVS Science and Technology Society, MRS, AVS, IEEE, and ASM.|
|Awards / Recognition|
|Awarded the Japan Society for the Promotion of Science (JSPS) fellowship of Japan government in 2001.|
|Publications and Patents Summary|
|He has published over 70 papers in the peer-reviewed international journals in the field of thin films, coatings, material science, and vacuum science and technology.
Submitted 10 disclosures for patent application.
|Training / Seminars|
|Taught courses of "Phase transformation in solid state", "Physical Metallurgy", and "Surface Engineering" for graduate students in the Department of Materials Science and Engineering, Huazhong University of Science and Technology, P.R. China.|
|Expert has experience locating vendors in the following areas: Metallurgical sample preparation and testing service, microhardness testers and testing services, thin film service companies, vacuum components, vacuum pumps, and different targets (Ti, TiSi, Al, TiAl, and Cr targets) used for physical vapor deposition of thin films and coatings.|
|Expert has experience developing, designing, and material selection for dental instruments, hermetic seal feedthrough for cardiovascular devices, hard disk writer head, and also characterizing, predicting, and improving reliability of dental instruments, feedthroughs, and magnetic recording heads.|