Applied Mechanics and Materials Vols. 423-426

Abstract: Convectional dryerswork at high temperature and usually lead to loss of quality for sensitivebiomaterial products (especially in nutrition). In this way the researchersfound the microwave power more effective and suitable for drying processes. Someof microwave drying advantages include the following: short drying time, highquality of product, low operating temperature, flexibility in producing widerange of products and easier process controlling. The article calculated themoisture content and drying rate during drying process. Microwave power, holdertray speed, dimension of samples, irradiation time were considered; under theseconditions experiments were done and the results show that microwave method hasmore advantages as comparing with convectional methods.

Abstract: The laser welding system is used to weld vacuum glass,the organizational structure of welding joint and the combining performance of the laser welding in different speeds are studied in this text. Under the same laser output power,welding combining performance and organizational structure are ideal both in the speed of 5mm/s and 10mm/s. It shows that laser welding is an effective method of the edge welding of vacuum glass. By comparison with experimental results, better solder welding joint organizational structure and combining performance can be obtained when the welding speed is 5mm/s than the welding speed is 10mm/s. It explains that appropriate laser welding speed is one of the effective methods of optimizing vacuum glass welding under certain laser output power.

Abstract: Diamond-like carbon films (DLC) were deposited on single crystalline silicon surface under different RF negative bias in microwave electron cyclotron resonance (ECR) plasma source. The chemical structure and morphology were characterized by Fourier transformation infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The friction coefficient of films was measured to examine the film property later. The results show that the smooth and compact deposited films were typical hydrogenated diamond-like carbon with CHn stretching vibration in 2800-3000cm^-1. It is noticed that with the increase of RF bias on the substrate the peak intensity for C-H stretching vibration in spectrum between 2800cm^-1~3000cm^-1 increased at the beginning and then decreased, which caused the friction coefficient of the film being smaller and then larger in reverse. In 50W RF biased power one can obtain the maximum-CHn peak intensity and the minimum friction coefficient.

Abstract: Accurate measurement for the flute curve of drill is essential to its design and the evaluation of cutting performance of drill. The helical flute curve of the drill has a big influence on the shape of the　main blade, the exhaust of the chip, and the supply of the coolant etc. In this paper the measuring method of flute curve is described. As the measuring method,　the lead, helical angle, normal section shape (flute curve) was measured respectively. Then the measured data are analyzed with digital filtering, smoothing etc., thus the normal section shape and cross-section shape data are gained. The measured data agree well with the known values. The proposed measuring method may be applied not only to the measurement of flute curve of the drill but also to the measurement of the other helical flute curves.

Abstract: Based on microwave digestion and dry digestion, the concentrations of Si, S, Ca, Cr, Fe, Ni, Cu, Al, Mo, Sb, Ti, V, Y and Zn in carbon fiber were determined using inductively coupled plasma mass spectrometry (ICP-MS). Compare with the concentrations in the solution got by microwave digestion, the concentrations in the solution got by dry digestion are higher. And microwave digestion is more suitable for treatment of carbon fiber containing volatile elements than dry digestion.

Abstract: In this work, a scrapped cross shaft which was assembled at the differential of ZL50C loader was analyzed by scanning electron microscopy (SEM) to examine the failure mechanism and was remanufactured by HVOF with ~500μm thickness WC-12Co coatings on it. The microstructure, phase compositions and properties of deposited WC-12Co coatings were investigated through optical microscope (OM), SEM, X-ray diffraction (XRD), microhardness tester and tensile testing machine. The results show that the coatings were very dense, and their porosities were lower than 1%. According to the X-ray Diffraction (XRD) analysis, the phase compositions of the sprayed coatings consisted of WC, Co and W₂C. The microhardness of the coating was approximated to 1100 HV_0.1 and the bonding strength was higher than 63.7 MPa. It can be concluded that WC-12Co coating sprayed by HVOF was suitable for the remanufacturing of shaft parts.

Abstract: In this paper, mathematic models of processing parameters and their adaptive learning principle in strip cold rolling mill are introduced. Exponential smoothing method is used during model adaptive learning. According to the contrast between actual and calculated data, adaptive learning coefficients in the process control models are modified, thus the precision of presetting model is improved. Based on three kinds of adaptive learning modes, corresponding model adaptive learning program is developed for strip cold rolling. The practical application shows that the accuracy of this method can meet the requirement of on-line process control, and it is suitable for process control in strip cold rolling mill.

Abstract: Molybdenum films with flat and smooth surfaces were prepared on Si (100) substrates using a pulsed laser deposition method. results indicate that increased laser fluence results in narrower diffraction peak, higher surface roughness, and transition from amorphous state into polycrystalline state with gradually increased grain size. The growth mechanism of the films and the effects of particle energy on the growth of the films are discussed based on an analysis of the changes in the crystallization process with laser fluence.

Abstract: Train bogie weld joint requirements with well toughness, high fatigue resistance and high resistance to overload. This article analied the weldability of SMA490BW steel, Combining with the characteristics of train bogie structure, a welding process scheme which had been used in practical productionwas worked out . Process testing and assessment results showed the process can obtain high quality welded joint.

Abstract: The connecting pipe in solar hot water system is made by TIG welding of thin-walled stainless steel and copper. As the welding of stainless steel and copper belongs to dissimilar metal welding and their physical properties are very different, thus the welding of them is difficult and it is likely to cause a variety of defects in the welding process. In this paper, ANSYS software is used to simulate the welding process of stainless steel and copper, and the temperature distributions in the welding process are obtained. The results show that: as the heat transferring of copper is faster than stainless steel, the temperature field distribution of thin-walled stainless steel and copper tubes in the welding process is extremely uneven. As a result, the melting degrees on both sides in the welding seam are inconsistent, which may cause poor forming of weld seam. The results provide references and theoretical basis for the welding technology of dissimilar materials.