Exact formulas for the power spectrum and signal-to-noise ratio (SNR) with periodic additive signal arecalculated in the linear system.Then the phenomenon of resonance is studied in detail.We show that resonancepeak a...Exact formulas for the power spectrum and signal-to-noise ratio (SNR) with periodic additive signal arecalculated in the linear system.Then the phenomenon of resonance is studied in detail.We show that resonancepeak and suppressed valley exist in the curves of the SNR versus the coefficient of self-saturation, the net gain and thecross-coupling coefficient of the laser system.展开更多
Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasiv...Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasive wear applications.This work focuses on transitions from tool steels to MMCs through a single pass laser powder deposition operation.Issues related to the application of various metal powders and carbides used include surface hardness,porosity,cracking,and dilution.These issues along with factory results that were obtained during this project are discussed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.10275025 the Natural Science Foundation of Hubei Province of China under Grant No.2005ABA051
文摘Exact formulas for the power spectrum and signal-to-noise ratio (SNR) with periodic additive signal arecalculated in the linear system.Then the phenomenon of resonance is studied in detail.We show that resonancepeak and suppressed valley exist in the curves of the SNR versus the coefficient of self-saturation, the net gain and thecross-coupling coefficient of the laser system.
基金Supported by the U.S. Department of Energy(DOE),Office of Industrial Technology under contract DE-PS0703ID14425:Industrial Materials for the Future Program and through contracts with Spirex Corporation and Owens-Illinois
文摘Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasive wear applications.This work focuses on transitions from tool steels to MMCs through a single pass laser powder deposition operation.Issues related to the application of various metal powders and carbides used include surface hardness,porosity,cracking,and dilution.These issues along with factory results that were obtained during this project are discussed.
