The application of heat-treatment-free cast aluminum alloys in automotive structural parts is increasing, but their weldability still unclear. This paper explores the resistance spot welding (RSW) die-casting alloy C611 utilizing an innovative electrode integrated with preheating and postheating techniques. single pulse, preheating, pulse processes were designed. Moreover, effects procedure on weld’s morphology, microstructure, properties compared analyzed. Results showed that process was...

Through questionnaire surveys combined with targeted data crawling, this study collects 445 valid samples of user contest participation behaviors on the Zhubajie platform using Gooseeker software. The research hypotheses are empirically validated through PLS-SEM (Partial Least Squares Structural Equation Modeling). Empirical results indicate that both internal and external motivational factors positively affect willingness. Internal significantly enhance users' innovation performance, while...

The tensile deformation behaviour and the fracture mechanism of 6Cr21Mn10MoVNbN alloy were studied in range between 25–800°C using thermal simulator, hardness tester, optical microscopy, scanning electronic microscopy attached with energy dispersive spectroscopy transmission microscopy. Elongation steel was found to decrease as temperature increases, which due growth coarse nitrides carbides precipitation Cr 2 N at grain boundaries. It also that differed different temperatures. At a low...

Twin roll casting is an attractive technology for producing aluminium sheets foils. But, surface defects, such as matte may occur on foils produced in this way. However, it not the case by traditional hot rolled process. Optical microscopy, scanning electronic energy spectrum and transmission microscopy were used to investigate effects of microstructures twin cast alloy sheet defects produced. It discovered that central segregation band microsegregation result a non-uniformly distributed...

Distribution network lines are numerous and widely distributed. Large numbers of them distributed in the harsh micro-topography micro-climate areas, which prone to suffer from freezing rain snow, then lead dumping tower breaking line. Ice melting deicing effective methods deal with ice disaster distribution networks. Combined years experience anti-ice Hunan, this paper systematically introduces lines. These include electric current ice-melting by AC or DC manual de-icing. According...

This paper proposed an observer-based output feedback tracking controller with constraints for the rigid-link flexible-joint space manipulator system considering dynamic damping caused by torque change. By combining Barrier Lyapunov function, backstepping, coordinate transformation, scaling, and globally exponentially convergent velocity observer, scheme maintains simplicity of independent design observer controller, where observation gains control can be designed separately.

Hot and cold rolled strip samples with surface defects such as black pockmark, sliver central cracking were collected from a compact production line followed by rolling. Microstructures chemical compositions of the studied scanning electronic microscopy energy dispersive X-ray spectroscopy. Four typical types on including spherical mould powder entrapment, centre linear entrapment hot rolling experiment in laboratory. It was observed that transformed into pockmark after process. Centre led...

Abstract 6Cr21Mn10MoVNbN is a new type of alloy used for heavy duty engines. Thermal simulation, metallography, X-ray diffraction and theoretical analysis have been to study the deformation behaviour at elevated temperatures. By introducing an internal variable parameter, constitutive equation has suggested dynamic calculation stress/strain curve this based on Zerrilli–Armstrong fcc materials. The data calculated using developed agree fairly well with experimental data. microstructure found...

This article proposes a fixed-time fuzzy disturbance observer–based adaptive integral sliding-mode spacecraft control scheme with consideration of input uncertainties and unknown nonlinearities. First, for the purpose satisfying time-varying output constraints simplifying computational process, an error transformation function is employed to convert constrained system into unconstrained one. Second, ensure superior transient-state performance, improved sliding manifold integrated nonlinear...

A novel estimation scheme for joint torque information is constructed by observer design method in the case that force/torque/velocity/acceleration sensors of manipulator are not available. Based on generalized dynamic scaling function and scalar filtering, globally exponentially stable with only position measurement presented this article. The main contribution lies development classic Nicosia performance improvements significant order reduction compared to existing results. Comparative...

This paper proposes a novel neural-network-based (NN-based) adaptive composite terminal sliding mode (TSM) control scheme for class of spacecraft systems with mismatched disturbances and input uncertainties. The key point the proposed is that multiple uncertainties are considered well-handled by combined second-order disturbance observer (SODO) method an NN. First, purpose handling disturbances, SODO applied to obtain exact estimation disturbances. Second, satisfying output constraints...

The macro-distribution of alloy elements in a billet affects its following processing property, and even the mechanical property finishing products. In this study AA1235 aluminum was twin-roll cast into with thickness 7.0mm. dissolved layer by layer. ICP-AES used to analysis element distribution through thickness. It has been found that Fe Si were concentrated at both bottom surface top billet. A higher concentration observed than owing density segregation. center had lowest these two...

the edge crack frequently occurs in hot rolled 5182 alloy. SEM, EDS,etc.are used to analyze factors leading cracks. It is discovered that high sodium content, and coarse intermetallic phase inclusion are main reason for these Meanwhile, some measures suggested be taken avoid this kind cracks: making sure content below 3 ppm; controlling casting process chemical composition phase; refining melting aluminium eliminate inclusion; setting a suitable scalping depth.

Fabrication of silicon carbide fibres reinforced composite (SiC/SiC) by chemical vapour infiltration (CVI) process was investigated in this research with the help both simulation and experimental set-up.CVI preform carried out through pyrolysis methyltrichlorosilane (MTS) over a broad temperature range at atmospheric pressure.The overall aim morphological description matrix (co-deposition Si, SiC C) during MTS CVI its state-of-the-art numerical calculation.Phase-field model developed...

Fe-6.5wt%Si silicon steel has excellent soft magnetic properties, but its ductility in room temperature is near zero. A lot of researchers tried to improve the by adding alloy elements. In this paper, we summarized action mechanism and content these elements according overseas domestic research status. Al, B, Cr, RE, et al. improved low temperature, reduced properties simultaneously. Ni, Ti, Mn, inconspicuously.

Abstract The change of operation mode the HVDC project causes a external characteristic converter valve, and reverse recovery thyristor inside valve changes accordingly. Therefore, charge measurement values thyristors under different operating conditions cannot be directly compared, status evaluated online. method measuring series based on turn-off voltage is presented in this paper. Then, analyzed, characteristics modes are discussed. Secondly, factors that affect analyzed essentially,...

Heterogeneity of composition and microstructure in cast large sized 3104 aluminium alloy slab were studied using AES-ICP, OM, SEM, etc. The results show that the cooling rate on cross section is different, macro-segregation found different .The content Ti decreases gradually from surface to about 1/4 thickness slab, then increases rapidly center slab; other elements center; grain size area fine, at coarse , segregation Mg within grains; great amount compound be presence boundary, with...

A new generalized class of fuzzy implications, called ( $h,f,g$ )-implications, is introduced and discussed in this paper. The results show that the implications possess some good properties, such as left neutrality property exchange principle.