Papers by Author: Bin Shi Xu

Abstract: The inner-lined layers bonding strength of the ceramic-lined tubing was measured from 25°C to 600°C. The macroscopic structure and microscopic characteristics of the slippage surface of the ceramic-lined tubing were observed using optical microscopy and scanning electron microscopy. Combined with finite element analysis of the residual stress distribution at different temperatures, the shear failure model of the ceramic-lined tubing at different temperatures was given. The mechanical bonding force at the C-A (ceramic layer-alloy layer) interface is greater than the metallurgical bonding force at the A-T (alloy layer-base tubing) interface at low temperature, and the mechanical bonding force at the C-A interface is less than the metallurgical bonding force at the A-T interface at high temperature. The transition temperature is about 200 °C.

Abstract: Variable polarity plasma arc welding has been widely used to manufacture industries. The effects of welding current and plasma gas flow as the most important parameters on variable polarity plasma arc pressure were discussed experimentally. To welding current, two experimental were designed to discuss the effects of straight polarity current and reversed polarity current on arc pressure respectively. It could be concluded that arc pressure is quadratic with welding current. To plasma gas flow, both experimental and numerical analysis are used to discuss the mechanisms of plasma gas flow to arc pressure, and it could be conclude that arc pressure is quadratic with plasma gas flow rather than linear.

Abstract: The nano surface engineering technology mainly concludes the nano-materials electric brush plating technology, nano-materials thermal spraying technology and nano-films solid lubrication technology. Through the nano surface engineering, the films or coatings possessing the nano-structure characteristics can be prepared, improving remarkably the wear-resistance, anti-corrosion and fatigue-resistance of the substrate. Although the nano surface engineering enriches the maintenance methods and advances the maintenance effects, it still stands the elementary development period and many fundamental issues deserve to research in depth.

Abstract: To explore a way to characterize fatigue damage degree of ferromagnetic materials by metal magnetic memory testing (MMMT), tension-compression fatigue test of specimens with different stress concentration factors made of 45% C steel were carried out. Both normal and tangential component of magnetic memory signals, Hp(y) and Hp(x), of specimens under different fatigue cycles were measured by EMS-2003 and RM-1 magnetic memory testing apparatus respectively. The results show that, the gradient variation of Hp(y) signals during the fatigue test is similar to each other, but the gradient value is different due to the different stress concentration factors. And so is the relative peak value of Hp(x) signals. Both gradient of Hp(y) and relative peak value of Hp(x) can be used to distinguish the stress concentration degree of specimens.

Abstract: Based on the foreign remanufacturing mode, the new remanufacturing rapid forming technology, which relies mainly on Surface Repair and Performance Improving Method has been explored and practiced. The aim of remanufacturing forming is to renew the original size of the waste components rapidly, and then improve their service performance. The advanced rapid forming technology, especially the high density heat source surface forming technology, is the important technique to carry out rapid forming. Based on the arc heat source, plasma heat source and laser heat source, three kinds of high density heat source remanufacturing forming technologies, such as high speed arc spraying forming technology, micro-arc plasma forming technology, and laser cladding forming technology, have been developed.

Abstract: The volume tendency of in-use and second-hand computers in China were analyzed, the emerging danger of second-hand computers by incorrect treatment was summarized, the integration disposal technologies based on remanufacture and reuse technology aiming at monitors, electronic devices, metals, plastics materials, and overall computers were put forward, the economic and social benefits were also analyzed. The results show that the integration disposal process of second-hand computer is an optimum approach to save the resource of electromechanical products. Remanufacturing and disposal 100 thousands second-hand computers per year could create profits about ￥10 millions and provide employment for 300 persons. It can be deduced that there are great potential opportunities for the second-hand computers disposal industry containing recycle, remanufacture and reuse engineering.

Abstract: It has previously been reported that when a fatigue crack grows in ferromagnetic materials, abnormal magnetic signals are spontaneously emitted, which can provide a powerful tool for fatigue crack life prediction. However, there is no physical model yet available to explain the mechanism for the formation of these self-emitting magnetic signals. In the present research, tension-tension fatigue tests of center-cracked sheet specimens were performed. The variations in the normal component of the self-emitting magnetic signals, Hp(y), on the surfaces of the specimens were measured during the fatigue test. The differences in peak-to-peak value, Hp(y), before and after failure of a specimen, were characterized. Consequently, a physical model based on magnetic charge was proposed, which was in good agreement with the experimental results. The model is helpful for understanding the inherent mechanism of the self-emitting magnetic signals.

Abstract: Fatigue damage degree of crankshaft remanufacturing core was studied based on Metal Magnetic Memory Testing. Bending fatigue test of crankshaft remanufacturing core was conducted on the resonant fatigue test rig and variations of two-dimensional magnetic memory signal distribution in crankshaft pin fillets were studied at different bending fatigue cycle. Experimental research shows that distributions of Hp(x) signals, namely, tangential component of spontaneous stray field and Hp(y) signals, namely, normal component of spontaneous stray field in crankshaft pin fillets have no obvious change with loading cycle when no crack initiation and propagation occur in crankshaft pin fillets. Characteristics of Hp(x) and Hp(y) signal both show dynamic variations when crack in crankshaft pin fillets initiates and extends at medium rate or high rate. Metal Magnetic Memory Testing is a dynamic method for monitoring fatigue crack propagation in crankshaft.

Abstract: This paper mainly introduced the causations of deep-sea submersible (DS) surface material damage and some methods of research on corrosion and fatigue. It is suggested that investigating the mechanisms and effects of corrosion and fatigue damage on DS steel structure and coating, and the mapping relation for the origin and accumulation of cross scale damage should be established. In addition, organic coating, metallic coating, steel matrix and their interaction could be detected and analysed using the methods of SEM, XRD, TEM, EIS, EN, CV, Kelvin probe and so on. At last, mathematical model of service life for the steel structure and coating should be established for the quantification study

Abstract: Spraying wire was widely used in remanufacturing work piece for worn failure. With the demand of high abrasion resistant wire, new type alloy was developed. The solidification structures of the new high abrasion resistant alloy (HARA) containing Mn, Cr, Si, C and the structure was studied after tension by scanning electron microscopy (SEM). The phase evolution was analyzed by X-ray diffraction and Rockwell hardness evaluated on the hardness testing. The abrasion behavior of HARA alloy used in the liner of wet-grinding machine in metallurgical industry is investigated under impacted energy of 0.5-3 J in acid-ironstone slurry; the test was carried out by a modified MLD-10 tester. The result show that the solidification structures of HARA alloy consist of austenitic Fe and the hardness neared to HRC60. Under the high energy, the wear resistance of HARA alloy is three times more than Mn13. Therefore, the new material has better abrasive wear resistance and lower environmental impact