Advanced Materials Research Vols. 1004-1005

Abstract: Fabrication of superhydrophobic structure by femtosecond laser become more and more popular in recent years, because it’s inexpensive and micro/nanostructure can be controlled compared with other methods. This paper proposes an approach to fabricate large scale superhydrophobic structure directly on nickel (Ni) surface by femtosecond laser and the apparent contact angle (CA) on the Ni surface can reach 134° without further coating any low surface energy materials. With low laser power, typical laser-induced periodic surface structures (LIPSS) at the submicron level can be observed. With high laser power, periodic ripples with microstructure covered by LIPSS can be observed. The micro/nanostructure on Ni surface is directly replicated onto PDMS and after replication the CA on PDMS surface can be improved to 153° obviously from CA of 120° on PDMS surface without micro/nanostructure. The higher laser power can results in the larger CA. This replication method can be applied for fabricating large scale superhydrophobic structure and the replication master can be used many times.

Abstract: This article selects the typical carving stone as the research object. We make an discuss about the factors affecting the effect of seal cutting art of using saber from the perspective of petrology through the conditions of seal cutting stone material, color, hardness, transparency and so on. Making an analyze about the adaptability to seal cutting stone and the stone material impact bit broken seal treatment , in order to select material of seal cutting lovers with reference.

Abstract: The portable measurement instrument is designed and built to measure the dynamic magnetic properties of the soft magnetic materials. The measurement principle and sampling method are presented. The study shows the instrument can measure the different types of soft materials accurately at frequencies in the range of 20 Hz – 200 kHz. The standard deviations of the specific total loss (P_s) and amplitude permeability (μ_a) are less than 0.3%. The errors of P_s and u_a are not larger than 0.3% between the measurement results of the instrument and the standard measurement device of National Institute of Metrology (NIM) of China NIM.

Abstract: In the capricious marine environment, the offshore platform structure is exposed to the multiaxial fatigue loading in which damage would be formed in different directions and planes. Evolution of the structural damage physical mechanism caused by marine environment load is more complicated. Based on the analysis of a large number of literatures, this paper reviews the research status of the fatigue crack mechanism in China and abroad, and predicts the development direction in the future.

Abstract: The microstructure transformation in large deformation upsetting process of TC16 is studied by means of optical microscope and microhardness measuring. The results show that the rolled and annealed TC16 titanium alloy presents tiny isometric crystal grain structure of α+β. When the deformation of the plate nut head is up to 94%, the upsetted shank is overexpansion and the edge of the head laps. The specimen is scrapped due to the widmannstatten structure at the upsetting temperature of 900°C. An adiabatic shear band, the hardness of which is higher than the matrix and surrounding, is observed and widens as the heated temperature rises. Both the size and microstructure of the specimen meet the requirements at the upsetting temperature of 850°C.

Abstract: This paper uses FLOTRAN to estimate the resin flow permeability of fiber tow in RTM. Nine models of different fractions varies from 0.4~0.75 have been built, and the random process of the fiber’s distribution is realized by APDL code. The results show that the dispersion of fiber determines the fluid flow channels, which effect the pressure and velocity’s distribution; the FLOTRAN can be used to estimate the transverse permeability of the fiber bundles.

Abstract: CBN wheel grinding performance on K9 glass is experimentally analyzed, which is using ultrasonic vibration assisted mechanical dressing, and dressing modes have different influences on grinding performance on the basis of the grinding surface morphology characteristics of K9 glass. The experimental results show that the CBN grinding wheel of vibration dressing mode has relatively large grinding ratio compared with ordinary dressing, and its microstructure on the grinding surface is strongly influenced by dressing modes and grinding speed.

Abstract: A mechanical model of axial ring rolling is established. According to the analytical method, the calculation formula of axial ring rolling contact area and unit rolling force is derived. On this basis the calculation formula of axial rolling force is derived. The influence of processing parameters on the axial rolling force is investigated. It is found that the axial rolling force increases with the increase of the outer diameter of ring, and the axial rolling force decreases with the increase of the inside diameter of ring. The greater the feed in axial direction, the greater the axial rolling force.

Abstract: Experiments on the dynamic behavior of ice in compression were carried out by means of SHPB apparatus. The specimens were to-10°C~-25°C and the tested strain rate ranged from 700/s to 1000/s. Strain-rate effects and the influence of freezing preserve time were studied. It was observed that the dynamic compressive strength of ice has an effect of strain-rate enhancement and the freezing preserve time has no influence to its dynamic compressive strength. In addition, a Pulse shaping technique to avoid the specimen failing before stress uniformity in ice specimen was presented.

Abstract: The assembly of a gantry type high-speed drilling machine was designed with 3D design software. The analysis of the static and dynamic of the gantry was performed by using a finite element software. The results show that, the existing model has perfectible dynamic and static performance, the safety factor of strength reaches 10.5, static stiffness is 186.6KN/mm, and can meet the requirements. The maximum amplitude of dynamic response of the gantry is reached at the third order modal when the rated spindle speed is 3400 RPM(56.7Hz). In order to avoid the resonance and to ensure the machine with longer service life and high manufacture precision, the spindle speed should be adjusted under 3000RPM. The analysis shows that the design of the existed model is reasonable. However during the further design and optimization, the designers can also reinforce the stiffness of the gantry by reducing the weight of the spindle boxes and increasing the torsional stiffness of the uprights.