This study focuses on arc-shaped 40CrNiMo steel; the microstructure characteristics and formation mechanism of hardened layer at different positions were investigated after laser hardening. Moreover, sliding friction experiments conducted against GCr15 steel conventional heat treatment under dry conditions, wear process parameters was analyzed, in stages studied. The results show that martensite reliefs within austenite grains have no effect each other. relief individual grain is closely...

In this study, a new method to reduce the in-band radar cross section (RCS) of circularly polarized microstrip antenna array (CPMAA) based on novel feed network is presented, which can independently regulate radiation and scattering performances without loading metasurface or modifying shape element. Using principle Van Atta antenna, 180° phase difference between waves reradiated by adjacent subarrays proposed CPMAA realized controlling transmission connected lines in network; thus,...

Abstract Shot peening is a commonly used surface-strengthening method, generates plastic deformation on material surface, introduces residual compressive stress, and improves the fatigue performance of materials. It widely in surface strengthening However, to further promote effect, this article proposes new induction heating composite shot (IHCSP) method that achieves 20CrMnTi gear steel. Based tensile, crack propagation friction tests, influence mechanism IHCSP mechanical properties,...

40CrNiMo steel, which is a commonly used material for sprag clutch wedges, widely in practice, and the surface wear will seriously affect performance of product. In this study, steel was strengthened at two scanning speeds by laser hardening. After hardening, hardness can reach use requirement wedge. By changing speed temperature, friction testing machine to study behavior after hardening against GCr15 under oil lubrication, coefficient, amount morphology different conditions were analyzed....

In order to understand the influence of blade angle on hydraulic characteristics a shaft tubular pumping device, energy characteristics, cavitation runaway and pressure pulsation device under different angles were studied by model test. Comparing efficiency best point angles, it can be seen that when is +4°, lowest, 74.10%. When −4°, highest, 79.75%. overall performance best. design head deviated, NPSHav (Net positive suction available) pump will increase. At same angle, speed increases with...

Purpose The aim of this paper is to solve the problem low accuracy traditional fatigue crack growth (FCG) prediction methods. Design/methodology/approach GMSVR model was proposed by combining grey modeling (GM) and support vector regression (SVR). Meanwhile, parameter optimal selection method based on artificial bee colony (ABC) algorithm presented. FCG 7075 aluminum alloy under different conditions were taken as study objects, performance genetic algorithm, particle swarm optimization...

This paper proposed a routing algorithm based on ant colony algorithm. The traditional updates pheromone according to the path length, get shortest from initial node destination node. But MIMO system is different SISO system. distance farther but energy not bigger. Similarly, closer distance, smaller necessarily. So need select consumption of path. update which cluster head next hop Then, can find communication least. save more network. simulation results MATLAB show that chosen by better...

The fatigue performance of high-strength Al-Cu-Mg alloys is generally influenced by the process creep age formation when applied to acquire higher strength. results show that aging accelerates precipitation process, leading a more uniform strengthening phases in grains, as well narrowed precipitation-free zones (PFZ). Compared with artificially aged alloy, yield strength and hardness alloy increased, but resistance decreased. In low stress intensity factor region (ΔK ≤ 7 MPa·m1/2), crack...

As mainstream of wireless communication system,digital system cannot directly transmit digital baseband signals that must be modulated at the sender before being sent into channel.Digital modulation is using to control parameters carrier, includes amplitude modulation, frequency and phase modulation.Noise existing in channel can seriously affect signal’s transmission performance.AWGN (additive white Gaussian noise) most simple radio channel, this paper aims performance analysis three kinds...

The surface of 40CrNiMo steel, which is commonly used for the sprag clutch wedge, prone to wear. In this study, hardening matrix material was conducted by broadband-laser scanning at various speeds. hardness distribution and structure evolution were analyzed along vertical direction. Characteristics hardened layer explored using electron microscopy, transmission X-ray diffractometry. friction coefficient, wear amount, morphology sliding against GCr15 steel investigated under conditions....

Retracted.