Advanced Materials Research Vol. 933

Abstract: A new algorithm is presented in order to search for the optimal solution of the manufacturing and fractional cell formation problem. In addition, this paper introduces a new toolkit, which is used to search for the various candidate solutions in a periodic and a waving (diversified) manner. The toolkit consists of 15 tools that play a major role in speeding up the obtainment of the final solution as well as in increasing its efficiency. The application of the binary digit grouping algorithm leads to the creation of manufacturing cells according to the concept of group technology. The nonzero entries, which remain outside the manufacturing cells, are called exceptional elements. When a lot of such elements is obtained, an additional cell called fractional (or remainder) cell may be formed; the aim of which is to reduce their number. This algorithm was tested by using illustrative examples taken from the literature and succeeded to give better or at least similar results when compared to those of other well-known algorithms.

Abstract: This work presents a review of the three most efficient non-destructive testing methods. The methods are radiography, eddy current and ultrasonic inspection. These particular techniques were chosen because they are able to cover most of the industrial needs for welding joint inspection. The aim of this work is to present the physical background of operation for the given methods, discuss their benefits, limitations, and typical areas of application, and compare them with each other. In the first part of this work, all three methods and their variations are described in detail with schemes and figures which represent their working principles. It appears that, although all the given methods can detect all types of flaws in welded joints, they have their specific limitations. For example, ultrasonic testing is able to detect defects only in certain directions. The eddy current technique is also sensitive to defect direction, but it can be applied for inspecting conductive materials only. The main flaw of radiography is the resolution: it is not usable for very fine defects. The second part of the work is for comparing the testing methods and for drawing the conclusions. The methods are compared according to the possible materials, defect types and their position, as well as the possible areas of application. This part gives the background for choosing a proper welding joint testing method for certain applications in the welding industry.

Abstract: Welding defects result infailure of the machinery and other negative consequences. Therefore, they need to be detected as they appear to ensure efficient and high-quality production. There is a raising interest in the implementation of sensors to provide highly accurate and robust real-time welding process monitoring. This work describes the four most widely used techniques of welding process monitoring. These monitoring techniques are arc sensors, optical sensors, infrared sensors, and ultrasonic sensors. This work explains their principles of operation: discuss their advantages and limitations and give typical areas of application. Arc sensors, optical sensors, infrared sensors, and ultrasonic sensors are described in detail with the necessary figures and schemes in the first part of the present study. The physical background, the strengths and weaknesses, and real life examples of the sensing techniques are given in this part. The results of the research show that each sensing method has its specific features thatcan play an important role in certain welding applications. Arc sensors do not requireadditional equipment in the welding zone. Thisis why they can be used where operational space is limited. Optical sensors allow the observation of the weld pool behavior. Infrared sensors can create the temperature profile of the weld. Ultrasonic sensors usually have good resolution and can provide accurate data. This paper will help welding engineers to choose the optimal sensing equipment for aspecific industrial application.

Abstract: Magnetizing roasting followed by magnetic separation is a compound technique for the beneficiation optimization of Huangmei refractory limonite. The natural limonite samples are obtained from Huangmei, Hubei province. The samples are characterized by TG-DTG-DSC. The content of major components is analyzed by SEM-XRAY, which is found that the sample iron mainly occurs in the form of limonite, with impurities including quartz, kaolinite, and barite. The feasibility of oxidized iron ore magnetic roasting limonite by multi-grade dynamic state magnetizing roasting is investigated. The effects of operation parameters such as roasting atmosphere, temperature and roasting duration are analyzed. The results show that: in the condition of the volume fraction of CO is 2% to 5%, the temperature is 700-780°C, and the roasting duration is 20 to 30 minutes. By multi-grade dynamic state magnetizing roasting, the grade of roasting limonite is nearly 33%, and the feasibility of separation is effective. A good index is created through simple mineral processing, the iron grade of concentrate reaches to 60% and the iron recovery rate reaches to 83.94%. It reveals that the multi-grade dynamic state magnetizing roasting device has a remarkable effect on roasting limonite.

Abstract: Titanium alloy tube has been widely used in various industries due to its good corrosion resistance, small proportion and high intensity. In this research, TA2 Titanium Tube has been deeply processed under different rolling speeds and heat treatment. Through the experiments the following conclusions have been made: rolling speed has little effect on the TA2 tube properties; the tube with 485°C by 3min induction heat treatment after rolling could obtain 534MPa tensile strength, 406MPa yield strength and 30% elongation. As heat temperature increasing, the microstructure of the TA2 tube transfers from fiber to equiaxial structure; the surface stress of the tube is tensile stress and heat treatment can reduce the surface residual stress.

Abstract: As the adhesive, not only has the mechanical properties and good heat resistance, but also has good durability, in order to assess the storage requirements for reliable performance of bonded parts in the process of the heat and humidity aging. In this paper the properties of starch based aqueous polymer isocyanate adhesive for wood under different hygrothermal aging, explore the aging mechanism of starch based aqueous polymer isocyanate adhesive agent hydrothermal conversion from the shear strength, glass transition temperature, scanning electron microscope, infrared spectrum analysis method.

Abstract: A tanning process based on a preliminary stabilization with glucose, followed by a chromium tannage, has been optimized on semi-industrial scale. A higher chromium content in the tanned leather and a better exhaustion of the floats indicate that the presence of glucose in the hide improves the penetration and fixation of chromium. The stabilization with glucose allows the production of chromium-free waste shavings that may be reutilized through more sustainable routes. The crust leather obtained is characterized by mechanical and technical properties comparable to those of the traditionally chromium tanned crust leather. As far as roundness, fullness and hand, the glucose stabilized leather display better performances. The results obtained assess the glucose stabilized leather as a good candidate for producing high quality bovine upper leather through a more environmental sound chromium tannage, in terms of lower chromium consumption and discharge in the wastewaters and of better reutilization of chromium-free wastes.

Abstract: It is a key point that the surface machining feature plays an important role on machined surface morphology of high speed milling hardened steel. The machining surface morphology surface morphology plays an important role in the formation of surface roughness. In this work, the machining features are the target that find the law of effect on surface morphology. We experiment on the concave and convex surface respectively, find out the influence law of surface morphology with different machining features in the process of high speed milling hardened steel. The results show that. The residual height is lowest along a sinusoidal line, it is times in vertical direction, and it is the worst in the 45odirection. The curvature radius influence the residual height , but the effect in the convex surface is more significant than that of concave surface. By changing the Angle can effectively relieve the effects that the curvature radius influences on surface residual height.

Abstract: In order to explore the effect of TiN and TiAlN coatings on tribological properties and efficiency of gear, TiN and TiAlN coatings were deposited on 45 steel and the surface of gears by Arc Ion Plating technique. The dry tribological behavior of the substrate and coatings were tested in a ball-on-disk tribometer. The microcosmic morphology of the wear areas were observed by scanning electron microscope and energy dispersive spectrum. The wear mechanism of TiN and TiAlN coatings were investigated to assess the performance of the coatings. The efficiency of uncoated and coated gear was obtained and compared at various input rotating speeds. The results showed that TiN and TiAlN coatings provide a significant decrease of average friction coefficients compared with substrate. The wear mechanisms TiN and TiAlN coatings are mainly abrasive and adhesive wear, accompanied with adhesive and oxidation wear. The efficiency of gear has been significantly enhanced after TiN and TiAlN coatings deposition.

Abstract: As for the phenomenon of the bottom thermal inward convex distortion of the Composite Bottom Pan (CBP) on the condition of heating, the mechanism of the bottom distortion was researched on the basis of ANSYS 10.0 considering the structural characteristic and the heating conditions of the composite bottom pan. The results showed that the thicker the bottom of the composite bottom pan, the smaller its thermal deformation amount. The thicker the junction of the pot and wall was, the smaller its deformation. And it was helpful for reduction of deformation to use a big rounded transition. The increase of rings number of magnetic conductive sheet would lead to a less bottom thermal inward convex distortion of the CBP. The larger the area of the additional stainless steel sheet (or ring), the smaller the deformation amount. Consequently, the research laid a solid theoretical foundation for the design and optimization of the structure of composite bottom pan.