Yang Qibiao

Bio: Yang Qibiao is an academic researcher from Hubei University of Technology. The author has contributed to research in topics: Surface modification & Polishing. The author has an hindex of 8, co-authored 74 publications receiving 220 citations.

Superhydrophobic micro-nano structures on silicone rubber by nanosecond laser processing

Abstract: This paper demonstrates laser surface modification of silicone rubber using an economic and efficient nanosecond fibre laser The resulting surface morphology shows that micro-nano structures leading to an increase in the surface slope were formed after processing The effect of laser power on the surface wettability was investigated demonstrating that the contact angle of the silicone rubber surface increased with increasing laser fluence The water contact angle on the treated surface reached ~160° with a rolling-off angle of ~3° when the laser fluence reached 10 J cm−2 After laser processing, both the roughness and root mean square slope of the silicone rubber surface increased with increasing fluence and reached maximum at a fluence of 10 J cm−2 An analysis of the pre- and post processing surfaces suggested there were no significant compositional changes, but there were some micro-structural changes to the polymer chain, namely, cleavage of the Si–O–Si bonds It is thus proposed that the hierarchical micro-nano structures and hence the change in the root mean square slope of the silicone rubber surface induced by laser irradiation are the primary reasons for its superhydrophobicity The preparation of superhydrophobic silicone rubber can have important applications in self-cleaning, anti-icing, and anti-pollution

Laser-structured superhydrophobic/superoleophilic aluminum surfaces for efficient oil/water separation

Abstract: The current demand for oil/water separation with an efficient, cost-effective, and environmentally friendly method is increasing. A laser-structured superhydrophobic/superoleophilic aluminum was prepared by using a nanosecond laser. The aluminum plate was used for oil/water separation without external force, which can replace the traditional porous materials. The effect of hole diameter and spacing on the effectiveness of oil/water separation is discussed. The results show that the aluminum plate with a hole size of 0.5 mm can be considered a more appropriate choice for the oil/water mixtures with large water content. In addition, complete separation of oil and water can be achieved in the hole spacing range of 1.0-3.0 mm. The oil separation speed can be increased without changing the water permeability by reducing the hole spacing, which is positively related to the hole spacing. Separation efficiencies were tested with various oil/water mixtures. The aluminum plate with a hole size of 0.5 mm can quickly separate the different oil mixtures with less than 50% oil content while achieving an oil separation efficiency of up to 99%. Due to the difference in dynamic viscosity of various oil phases, the separation efficiencies of the petrol, kerosene, and diesel are slightly different but can still be maintained above 99%. The laser-processed aluminum plate has several advantages of high porosity, high surface of superhydrophobic properties, and easy tunable structures. In practical applications, the hole size and the spacing should be appropriately adjusted according to specific conditions, such as different oils, the mixing ratios, etc., to obtain the best separation efficiency and speed.

Nanosecond laser surface processing of AlN ceramics

Abstract: To study the formation mechanism of a conductive layer in a laser-processed AlN ceramic plate, nanosecond laser treatment on an AlN ceramic was performed to generate an Al layer, which created conductivity on the surface. Changes in the resistance for different energy densities, pulse durations, line spacings and scanning speeds were studied by means of XPS and scanning electron microscopy. The results show that the resistance is inversely proportional to the duration of the pulse in the case of low energy density or low scanning speed. At a higher energy density or a higher scanning speed, the resistance is proportional to the duration of the pulse. The variation in the resistance as a function of line spacing is related to the energy density. As the energy density increases, the resistance value decreases slowly at first and then maintains an upward trend. The resistance is proportional to the scanning speed.

Fabrication of Carbon Nanotubes/Cu composites with orthotropic mechanical and tribological properties

Abstract: In this work, Multi-Walled Carbon Nanotubes reinforced copper matrix composites were prepared through a series of preparation processes including ultrasonic and nitrogen-assisted mixing, electroless Nickel–Copper bilayers plating, hot extrusion and cold drawing. The mechanical and tribological properties of the composites were enhanced with the increase of MWCNTs. The Cu matrix composites enhanced with 10 vol% MWCNTs showed significant improvements in the mechanical and tribological properties. Compared with the pure Cu sample prepared by the same method, the tensile strength and yield strength of the composite increased by 52.15% and 56.67%, while the friction coefficient and wear rate decreased by 66.8% and 62.3%, respectively. Better than most of the reported data. The 3 vol% MWCNTs in the composites exhibited the highest strengthening efficiency. Due to the directional arrangement of the MWCNTs in the Cu matrix, the composites showed obvious orthogonal anisotropy, and the properties in the parallel drawing direction were much better than those in the vertical drawing direction. Dislocation and load transfer effect are considered as the main mechanism of mechanical properties enhancement. The formation of self-lubricating layer, load transfer, efficient derivation of friction heat and orientation arrangement of MWCNTs were the reasons which lead to the friction performance enhancement.

Characteristics of serrated chip formation in high-speed machining of metallic materials

Abstract: A study on the mechanism of serrated chip formation has been carried out. Characterization of serrated chip is performed using geometrical methods, including degree and frequency of segmentation, base angle, and bottom edge. Mechanical characterization such as micro-hardness is also adopted. Experiments of high-speed machining on three metallic materials including Ti6Al4V, hardened 1045 steel, and Al7050 are performed. The chips of the three metallic materials under different cutting speeds are collected during high-speed machining. After polishing, the serrated chip is observed under a digital microscope. The results show that the degree and frequency of segmentation increase with the cutting speed. Al7050 is most sensitive to these parameters. The hardened 1045 steel is similar to the titanium alloy Ti6Al4V. Both the base angle and the vertex angle decrease with the cutting speed. The specific geometry of serrated chip unit under certain cutting speed can be determined by using the geometric characterization parameters. The micro-hardness of the four vertices increases with the increase of cutting speed.

Laser Material Processing

Abstract: Processing of Laser Materials have a variety of industrial operations in which work piece is modified by laser operation, for example, by melting it or removing material from it. In recent years, laser based technologies became important or even dominant in industrial applications such as welding, cutting or drilling. Manufacturing technology will rely on lasers and laser-based material processing for the development of new material processing methodologies and multi-functional device integration solutions. Further possibilities of processing, innovation, and advancement of laser material treatments are still in progress and very challenging. The very broad field of laser materials processing is still very fast developing. To extend this developing field of material processing, a well-organised database can give a noble guideline and great reference. That can be used as fundamentals for any research or it may help industry to choose right type of laser for specific techniques.