Advanced Materials Research Vols. 154-155

Abstract: Wollastonite was inorganic modificated by coating aluminium silicate with heterogeneous deposition method.SEM, XRD, FTIR, BET surface area analyzer were used to characterize the product. XRD result shows that wollastonite is coated with nano-aluminium silicate. BET result shows that the specific surface area of particles increases by 200%. FTIR result shows that the content of OH group increases.Whiteness test shows that the whiteness increases by 2.0. Application test shows that the polypropelyne(PP) products filled with inorganic modificated powder have superior physical properties or mechanical properties(tensile strength 20.45Mpa, bending strength 38.02Mpa) than that with uncoated wollastonite and pure PP and the heat distortion tempeature increases by 28.6°C than pure PP.Inorganic modification of wollastonite can improve the joint interface between wollastonite and PP.

Abstract: In this paper, 4Cr5MoSiV1 steel is dealt with by QPQ salt-bath nitriding at 520°C, 540°C, 560°C and for 2h、4h、6h, respectively. The treated surface microstructure was analyzed by using SEM. The depth of nitriding layer, scratch hardness and wear-resistance were tested for QPQ salt-bath nitriding technology. The corrosion resistance was tested in the 5%NaCl water by using spraying method. The experimental results indicate that with increasing the temperature and the nitriding time, the depth of nitriding layer, scratch hardness and wear-resistance of 4Cr5MoSiV1 steel were increased greatly. Comparing with the untreated specimen, its hardness enhances 196.73%, wear resistance enhances 349.65%, anti-corrosion enhances 943.10%. The die hardness, wear resistance and the corrosion resistance can be greatly improved by using the QPQ salt-bath nitriding technology.

Abstract: Based on the broadly obtained experimental results, a particular simulant curve was firstly given to visually describe the variety of friction coefficient (μ) with the thickness of sulfide layer on hard steel substrate. The curve includes two inflexions named super-critical thickness (tC2) and sub-critical thickness (tC1) respectively. By means of “micro-peak and soft/hard plane” contact model given in the present work, physical definition and influence factors of tC1and tC2 were discussed in detailed. Theory analysis presents that a friction-reducing coating would obtain a minimum of μ at tC1，and good friction-reducing and anti-wear behaviors with its thickness range from tC1to tC2. Therefore, it is beneficial to improve tC2 or decrease tC1, especially keep a wide difference ( tC = tC2 - tC1). Herein, two optimized designation principles of the sulfide layer on a hard steel substrate were presented, which apparently apply to all lubricate situation with soft layers.

Abstract: Products made from double-layered hollow vacuum forming are widely used for their various advantages. The hollow vacuum forming process has been studied in this paper. Numerical simulation method for the hollow vacuum forming process of double-layered plastic sheets has been introduced by the simulation software Polyflow, which is suitable for viscoelasticity fluid bodies. This method can vividly and intuitively estimate the thickness, temperature variation and distribution in the double-layered vacuum forming processes. Based on this method, reliably theoretical calculation data can be provided to design the reasonable vacuum forming process for double-layered vacuum forming of new materials or new products. The proposed method has been verified to be applicable and effective by prototype fabrications.

Abstract: The choice of the process parameters in the conventional tube bending forming is often based on experience. The method of constantly testing to adjust has seriously affected the production efficiency and increased production costs. In this paper, an intelligent prediction model of the tube bending forming process parameters for utility boiler was set up based on neural network, which has been used to predict the main process parameters including the bending moment and boost power. In the intelligent prediction model, the analytical calculations, numerical simulation and experimental data are selected as the source of training samples. The test results show that the average relative error between the simulation output and target output of bending moment and boost power is less than 2%, and the predicted process parameters, i.e. bending moment and boost power, can be directly used for actual production.

Abstract: CrZrCu is extensively used in spot welding due to their high electrical, thermal and mechanical performance. But when CrZrCu electrode is used in spot welding of galvanized steel sheet, the abrasion, corrosion and oxidation shorten the electrode life rapidly. The electrode is not able to meet the needs of spot welding of galvanized steel sheet .In the paper, double glow plasma discharge surface titanizing was carried out on CrZrCu alloy. The processes of double glow plasma discharge titanizing, surface alloying layer structure were also analyzed elementary. The wear resistance property of glow discharge plasma titanizing layer was also researched. The experimental results indicated that in the plasma titanizing alloying layer, the diffusion of titanium element toward the interior of the CrZrCu alloy substrate forms the intermetallic compound named Cu4Ti, which is beneficial to the reinforcement of CrZrCu substrate. The experimental results confirmed that double glow plasma discharge titanizing could improve the wear resistance of CrZrCu alloy greatly. Under the external load of 300N and 500N, the wear resistance of double glow plasma discharge titanizing layer is7 times and 8.5 times than that of CrZrCu.

Abstract: The 3D design technology of the punching die of the automobile panel is discussed, and the basic thinking of the 3D die design based on UG surrounding is introduced. The parallel idea combined the 3D parameterized model with the 3D design of the die is presented. Every kind of resource library of the die design and its application are also introduced in this paper. Furthermore, the matters needing attention in the punching die design of the automobile panel are put forward in order to improve the efficiency and quality of the die design.

Abstract: Effect of rare earth content on microstructure and interfacial reactions of low Ag content SnAgCu solder is researched by adopting the X-ray diffraction, JSM-5610LV scanning electronic microscope, energy spectrum analysis and JEM2100 ultrahigh resolution electron microscopy. The results show that proper quantities of rare earth (0.1%) can refine the eutectic microstructure of the solder alloy; and petal-like rare earth compound can be found in the solder alloy while the rare earth addition is 0.5%. The growing rate of the interfacial intermetallic compound can be reduced during the soldering with adding 0.1% rare earth in the Sn2.5Ag0.7Cu solder alloy.

Abstract: The Fomichev plug is of characteristic producing equal unit-reduction of wall thickness along its perforation section during seamless tube piercing. This paper introduces the design of a novel Fomichev plug based upon the analysis of roll opening, taking into account for both feed angle and toe angle of a cone type piercer, then presents a 3-D coupled thermo-mechanical simulation of the novel Fomichev Plug’s performance characteristic during cone-roll piercing process, with the aid of FE code MSC.SuperForm. In comparison with conventional plugs, as FEM simulation result shows that the new plug makes the metal deformation distribute uniformly along its perforation section, which brings about well-distributed plug wear. The novel Fomichev plug is able to decrease the slip between the roll and workpiece and avoid rolling block owing to its smaller plug force, which can increase piercing efficiency so, moreover, analyzing stress distribution, it’s more suitable for metal deformation with fewer defects in tube piercing, makes resistance to metal elongation smaller, reduces wedge cleaving to tube billet, and prevents lamination defects during piercing high-alloy billet.

Abstract: For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. In this work, orthogonal experiment of diamond cutting was carried out on soda-lime glass, and the result of tool wear test was detected by utilizing confocal microscope. Extremum difference analysis was employed to research the influence of different cutting condition on tool wear. The characteristics and mechanisms of tool wear in diamond cutting of glass were revealed and interpreted.