Advanced Materials Research Vols. 139-141

Abstract: In this study, a sodium hydroxide modified soybean protein adhesive (NSP adhesive) was prepared and mixed with phenol-formaldehyde (PF) resin in a ratio of 7:3 to form a compound adhesive (NSPF adhesive), and three-layer plywoods were prepared using the NSP adhesive and the NSPF adhesive. In order to understand the reactions between SP and PF resin during the curing process of NSPF adhesive, the SEM and FTIR spectra were employed to character the adhesives and the bonding strength of the plywoods was measured. The results showed that the bonding strength of the poplar plywood prepared with NSPF reached 1.00 MPa, and met type I plywood requirement in GB/T 17657-1999. There was new absorption peak appear at 1390 cm-1 in the FTIR spectra of NSPF adhesive, indicating that there were -NHCH2- structures generate in NSPF during the curing process in this research.

Abstract: This study prepared a wood-based hydrogel, which was studied as a fertilizer controlle and release carrier. The wood-based hydrogel was prepared by solution polymerization and whose structure was characterized by FTIR spectra. The water absorbing capacity and urea adsorption capacity were studied. The result shows that: With increasing degree of grafting yield, the water absorption increased at first and decreased afterward. The maximum appear at the glutaraldehyde amount of 0.4 times. The urea adsorption of the wood-base hydrogel has a strongest value in 10% aqueous solution of urea. The drug loading changed by the degree of crosslinking hydrogel and the wood content in the wood-based hydrogel. Hydrogel has a good adsorption capacity of urea,the hydrogel water absorption and urea absorption ability can be adjusted by the grafting rate. The wood powder prepared hydrogels is a new environmental protection materials, which has good prospects in controll and release of pesticides and fertilizers

Abstract: A distributed system can be defined by three dimensionality: hardware, control functions and information data base. This paper introduced an example of the implementation and its design philosophy for a smelting and gas treatment project with their hardware and field control functions distributed by intelligent fieldbus devices and some modeling control functions and advanced control functions distributed to different data base in different segment stations. System integration was implemented successfully not only for their hardware, but also for their control functions and information data bases. Benefit of this project also can be obtained with respect to engineering, operation and maintenance.

Abstract: Effects of several different additions on microstructures in in-situ Mg2Si/A1-Si composites were investigated. The results show that rare earth elements have a selective modification effect on eutectic Mg2Si and Si structures. Al-Ti-B modifier should be introduced appropriately more into the composite, so as to effectively refine primary α-Al grains. As (SrCl2+RE) added increases from 0.4wt% to 2.0wt%, morphology of primary Mg2Si in a 12.0Mg2Si/A1-7.6Si composite is changed from polyhedron (or octahedron) to more irregular polyhedron with a size decrease from about 21μm to 6μm, while eutectic Mg2Si is changed from coarse dendrites to dispersed slim fibers. (RE+Al-P) can improve microstructures and tensile strength of a 7.9Mg2Si/A1-7.8Si composite; after modified by 0.8wt% (RE+Al-P), fracture surface of the composite is changed from cleavage to a mixed mode.

Abstract: The atom transfer radical polymerization is successful for synthesizing the topological type PMMA with α-D-glucose/2-bromoisobutyryl bromide as initiating system, CuBr as catalyzer and PMDETA as ligand. PMMA synthesized by such method has a controllable relative molecular mass and structure. The narrow distribution of relative molecular mass really achieves the controllable activity of ATRP.

Abstract: Tool wear reduction is very important in cutting of ultra hard and brittle materials. In this paper, a tool-swinging cutting method was applied to reduce the wear of round-nosed diamond tools in cutting of tungsten carbide (WC). In this method, the geometrical center of the cutting edge was adjusted to be in coincidence with the rotation center of the B-axis table, and thus the cutting point could be changed along the cutting edge by swinging the tool about the B-axis center. Experimental results showed that the width of the flank wear land was greatly reduced compared to that in the conventional cutting. This work can shed light on ultraprecision machining WC parts without or with less need for subsequent polishing process.

Abstract: Multi-array hole-entry hybrid journal bearings have been widely applied to support the high speed precision machine tool spindle with small diameter used in high efficient inner grinding, due to their prominent properties of high rotation accuracy, high dynamic stiffness, high vibration damping and long life. But the imperfection of the hybrid bearing is the significant temperature rising in the oil film on the condition of high speed operation, which brings about the sharp decreasing of load capacity and the larger thermal deformation of the bushing that cause the bearing failure immediately. In this paper, CFD analysis of the temperature fields of the multi-array hole-entry hybrid journal bearing with various bearing construction parameters and operation parameters are presented. According to the simulation results, the temperature rising in the oil film can be controlled efficiently by optimizing the matching of the bearing construction parameters and operation parameters and excellent characteristics of load capacity and static stiffness have been obtained simultaneously.

Abstract: Die and mold are constructed with various free surfaces. In the machining of die and mold, it takes a long time to finish the curved surface. In this study high accurate polishing technique by GC (grinding center) with elastic ball type wheel is developed. In polishing process it is very important to remove cusp height without decreasing machined form accuracy. It is available to use GC in free surface grinding and finishing of die and mold with elastic ball type wheel. In polishing process only cusp height is removed in order to keep form accuracy that is produced in cutting process with ball end mill. In order to know the polishing characteristics of elastic ball type wheel, basic experiments were conducted. The polishing parameters Sp. were obtained experimentally by changing the values of polishing process. Using polishing parameter, removal amount can be obtained and polished surface is possible to estimate.

Abstract: The development of chip morphology, critical cutting condition of adiabatic shear during serrated chip formation and cutting forces were observed and measured by high speed turning experiment for 30CrNi3MoV hardened steel. Results show that the cutting speed and rake angle are leading factors to influence chip morphology and cutting forces. With the increase of cutting speed, the continuous band chip transforms into serrated chip at a certain critical value. As the rake angle is changed from positive to negative, the critical cutting speed of adiabatic shear significantly decreases, the cutting forces abruptly reduces when the serrated chip forms. The results from predicting critical cutting speed using the critical cutting condition criterion of adiabatic shear in metal cutting process show that the leading reason of serrated chip formation is that the adiabatic shear fracture repeatedly occurs in the primary shear zone.

Abstract: Milling process will be dominated by multiple delays due to the effect of the cutter runout or the pitch angles of the cutter. In this paper, research efforts are focused on the dynamic behavior of milling processes under different cutting condition parameters such as different radial immersions, feed directions, feeds per tooth and helix angles. To improve the prediction accuracy of stability lobe, the combined influences of feed rate and cutter runout on the stability lobes are also taken into account. The basic principle of the method presented in one existing work is applied to examine the asymptotic stability trends for both down milling and up milling. Some new phenomena for certain combinations of cutting parameters are shown and explained in detail. It is found that as cutter runout occurs, feed per tooth, feed direction and cutter helix angle have great effects on the stability lobes.