Keynote Speaker| 主讲嘉宾

A.Prof. Xinmin Shen (Army Engineering University)

Title:Optimization of sound absorbing performance of porous metals
Abstract:Applications of porous metals in pollution control of urban noise make it a focus of research in the field of acoustics, because noise pollution greatly damages physical and mental health of humans and it can generate some diseases. Through measuring the sound absorbing coefficient based on standing wave method, 5 groups of experiments are conducted to investigate the sound absorbing performance of the porous metals with cavity under a limited dimension of 30 mm. There are two options can meet the requirement that the sound absorbing coefficients are larger than 70% in 2000-5000 Hz. Meanwhile, influences of compression ratios on the sound absorbing performance of porous metal are investigated. The samples are compressed with ratios from 10% to 80% at an interval of 10%. Based on the modified Johnson–Allard model with a correction factor, the sound absorption coefficient of the porous metal with a thickness of 20 mm for different compression ratios is derived, whose aim is to quantificationally analyze influences of the compression ratio. The results indicated that the sample with a compression ratio of 70% exhibits optimal sound absorption property, and its average sound absorption coefficient reached 88.97% in a frequency range of 1000–6000 Hz. Meanwhile, the section morphologies of these samples are investigated by a scanning electron microscope, which studied the sound absorption performance by analyzing structures of the porous metal. The results will promote the application of porous metal in the field of acoustics and improve the sound absorbing theory of porous material.

Keynote Speakers

Junbin Ke(Fujian Universtiy Of Technology

Title:The study of properties of TiSi/C、TiSiN/C and TiSiO/C multilayer films prepared by high power pulse magnetron sputtering
Abstract:This paper studies the effect of nitrogen or oxygen on the properties of TiSi/C hard films. Three sets of nano-multilayer composite hard films TiSi/C, TiSiN/C and TiSiO/C were prepared on tungsten carbide, 304 stainless steel and Si wafer substrates by high-power pulsed magnetron sputtering and DC magnetron sputtering. Meanwhile, X-ray diffraction (XRD), field emission-scanning electron microscope (SEM), Vickers hardness tester, tungsten carbide ball friction test, Raman spectra and electrochemical corrosion tests were performed to investigate the effects of nitrogen or oxygen on the microstructure, mechanical properties, tribology and corrosion resistance of TiSi/C films. The results show that the hardness of TiSiN/C film is 27.7% higher than that of TiSi/C film, and the hardness of TiSiO/C film is 67% higher than that of TiSi/C film. Besides, the hardness of the TiSiO/C film reaches 3771 HV, the friction coefficient is only 0.25, and the corrosion resistance is also the most excellent.

Yan Ma (Nanjing University of Science and Technology

Title: Corrected Internal Ballistic Simulation of High Chamber Pressure Gun
Abstract: In view of the high initial velocity and chamber pressure of the high chamber pressure gun, the equation of state of gunpowder gas which is closer to the actual situation is adopted. Then considering the influence of the air resistance at the front of the projectile, the change of the combustion speed parameter in different pressure sections, both the specific heat ratio of the gunpowder gas and the constant volume specific heat change with the pressure and temperature, and the effect of erosive burning. The traditional classical internal ballistic model is modified, the corresponding physical and mathematical models are established, the analogous calculation programs are compiled, and the theoretical calculations and experimental results are compared. The results show that compared with the traditional classical internal ballistic model simulation, the simulation results of the modified ballistic performance of the high chamber pressure gun are more consistent with the experimental results.

Yin Du(Guangxi University Of Technology)

Title: Intelligent Manufacturing: a Way to Upgrade Manufacturing Industry
Abstract: From manufacturing industry to intelligent manufacturing industry, China's manufacturing industry is entering a new intelligent production mode on a large scale. With the implementation of 4.0 policies in China's industry, it has further stimulated the endogenous power of the development of intelligent manufacturing in Chinese enterprises, and accelerated the development of intelligent factories and digital production workshops. The new production system of intelligent manufacturing emerges as the times require. In intelligent manufacturing, manufacturing enterprises implement individualized flexible production and control production cost according to market demand. This undoubtedly puts forward many new requirements for its production mode. 2018 can be said to be the key year to promote the development of intelligent manufacturing in China. In this trend, the traditional manufacturing industry upgrading is particularly important and has attracted much attention.