Advanced Materials Research Vol. 1089

Abstract: Ultra-fine heavy calcium carbonate functional filler was prepared by aluminum titanium complex coupling agent with mechanical chemical methods and characterized by IR and SEM. The results show that the optimum conditions of mechanical chemistry preparation of heavy calcium carbonate functional filler: the modifier dosage is 1% (mass fraction), the milling time is 2.5h, and grinding ball ratio is 35:45. Under the optimal conditions, the activated degree of heavy calcium carbonate is 99.5%, the particle size of D₅₀ is 4.56μm, and D₉₀ is 9.72μm. FIR and SEM analysis show that the surface of modified heavy calcium carbonate has been coated aluminum and titanium complex coupling agent.

Abstract: Laser peening is a novel surface treatment process that generates deep compressive residual stresses and microstructural changes and thereby dramatically improves fatigue strength of critical metal aircraft engine parts. In order to study the effects of laser peening on properties of TiAl alloy, Surface micro-hardness, microstructural, residual stress and pole figures before and after laser peening were tested. The experimental results showed that surface micro-hardness increased by 23%. The compressive residual stress increased 20 times. The texture in the normal direction of 8J peened sample showed a strong fiber texture components 10o away. In conclusion, the laser peening could improve properties of TiAl alloy.

Abstract: Greenhouse rolling machine is an important equipment of modern agriculture. It is widely used for curtain rolling in greenhouse. The overall structure of greenhouse rolling machine is designed. It uses composite gear system. According to its mechanical requirement, the machine transmission gear materials, steel 45 and 20CrMnTi alloy steel, are selected out. In order to improve the materials’ mechanical property, the materials have been treated by heat. The mechanical property, such as hardness, strength, toughness, etc, when quenching and tempering at different temperatures, is studied. The result provides a theoretical basis for the design of bearing capacity of the rolling machine.

Abstract: The color of the asphalt is close to black, it has the good ability of absorbing the solar energy. Road asphalt are solid or half a solid state at normal temperature, it must be reduced the asphalt viscosity to a certain range before used it. The main method of reducing the viscosity of asphalt is heating it. Because of the high temperature of the construction of asphalt, the traditional method on the asphalt heating is electrical heating which needs to consume large amounts of energy. Solar energy is huge and clean energy, which can save large of energy on the asphalt heating. This paper expounds on the solar heating principle, as well as designs the solar heating device to research the energy-saving method on the heating of road asphalt.

Abstract: An experiment of face milling of Invar36 was conducted by using coated carbide insert, the microhardness was tested and the metallographic structure was observed to figure out the principles of work-hardening. The results showed that the depth of work-hardening ranges from 80μm to 160μm among the parameters selected in the experiments. The degree and the depth of work-hardening were significantly affected by the axial depth of cut and feed per tooth. The degree and the depth of work-hardening showed a tendency to increase with the increase of the axial depth of cut and feed per tooth. Compared with the axial depth of cut and feed per tooth, cutting speed had less influence on the degree and depth of work-hardening. The degree and depth of work- hardening decreased slowly with the increase of cutting speed. Metallographic observation showed that work-hardening layer consisted of the thermal force influenced layer and the force influenced layer, while the amorphous metallographic structure was observed in the thermal force influenced layer, and lattice distortion was observed in the force influenced layer.

Abstract: The physical friction system model was established between the tool and the chip based on the analysis of tri-bological behavior of high speed milling process of the end mill. The finite element simulation method was employed to study the tool-chip friction model, and the two-dimensional(2D) finite element model of milling was created. The numerical results revealed the chip morphology, stress and temperature distribution of the tool-chip contact surface. The tool temperature field distribution provided supports for tool-chip friction state theory and the 3D milling model.