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Effect of Extrusion Temperature on the Mechanical Properties and Corrosion Behavior of LZ91 Alloys

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Acta Metallurgica Sinica(English Letters) 2023年第11期36卷 1822-1832页

作者： Xuejian Wang Huaqiang xiao Keqiang Su Bo Lin Tongmin Wang Enyu Guo School of Mechanical Engineering Guizhou UniversityGuiyang550000China Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Ningbo Institute of Dalian University of Technology Ningbo315000China

Microstructural observations,tensile tests,potentiodynamic polarization measurements,and corrosion morphology examinations are conducted to investigate the effect of extrusion temperature on the mechanical properties and corrosion behavior of LZ91 alloys.The results show that the tensile strength of the LZ91 alloy is increased by 86 MPa after extrusion at 25℃.Meanwhile,the corrosion resistance is improved by about 2.7 times,and the maximum corrosion depth is decreased by 60μm.The increase in the tensile strength can be mainly attributed to theα-Mg precipitate strengthening inβ-Li.The improvement of the corrosion resistance is due to the fact that the nano-sized MgLiZn and refinedα-Mg precipitates inβ-Li weaken the effect of the cathodic phase on micro-galvanic corrosion,thereby decreasing the cathodic current density and local corrosion susceptibility.However,when the extrusion temperature is increased to 300°C,the corrosion rate is significantly accelerated due to the increase of the micro-galvanic corrosion caused byα-Mg precipitate coarsening at high temperatures.

关键词： Mg-Li alloy Extrusion temperature Mechanical properties Corrosion behavior

Industry-Oriented Detection Method of PCBA Defects Using Semantic Segmentation Models

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1438-1446页

作者： Yang Li xiao Wang Zhifan He Ze Wang Ke Cheng Sanchuan Ding Yijing Fan xiaotao Li Yawen Niu Shanpeng xiao Zhenqi Hao Bin Gao huaqiang Wu Department of Internet of Things Technology and Application China Mobile Research InstituteBeijing 100053China Beijing Advanced Innovation Center for Integrated Circuits the School of Integrated CircuitTsinghua UniversityBeijing 100084China SigmaStar Technology Limited Xiamen 361199China IEEE

Automated optical inspection(AOI)is a significant process in printed circuit board assembly(PCBA)production lines which aims to detect tiny defects in PCBAs.Existing AOI equipment has several deficiencies including low throughput,large computation cost,high latency,and poor flexibility,which limits the efficiency of online PCBA inspection.In this paper,a novel PCBA defect detection method based on a lightweight deep convolution neural network is proposed.In this method,the semantic segmentation model is combined with a rule-based defect recognition algorithm to build up a defect detection frame-work.To improve the performance of the model,extensive real PCBA images are collected from production lines as datasets.Some optimization methods have been applied in the model according to production demand and enable integration in lightweight computing devices.Experiment results show that the production line using our method realizes a throughput more than three times higher than traditional methods.Our method can be integrated into a lightweight inference system and pro-mote the flexibility of AOI.The proposed method builds up a general paradigm and excellent example for model design and optimization oriented towards industrial requirements.

关键词： Automated optical inspection(AOI) deep learning defect detection printed circuit board assembly(PCBA) semantic segmentation.

Preface to the Special Issue on Beyond Moore: Resistive Switching Devices for Emerging Memory and Neuromorphic Computing

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Journal of Semiconductors 2021年第1期42卷 31-32页

作者： Yue Hao huaqiang Wu Yuchao Yang Qi Liu xiao Gong Genquan Han Ming Li School of Microelectronics Xidian UniversityXi’an 710071China Institute of Microelectronics Tsinghua UniversityBeijing 100084China Department of Micro/nanoelectronics Peking UniversityBeijing 100871China Frontier Institute of Chip and System Fudan UniversityShanghai 200438China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117546Singapore Institute of Semiconductors Chinese Academy of SciencesBeijing 100083China

Traditional charge-based memories,such as dynamic random-access memory(DRAM)and flash,are approaching their scaling limits.A variety of resistance-based memories,such as phase-change memory(PCM),magnetic random-access memory(MRAM)and resistive random-access memory(RRAM),have been long considered for emerging memory applications thanks to their non-volatility,fast speed,low power,and compact size for potentially high-density integration.

关键词： flash approaching random

Preface to the Special Issue on Beyond Moore:Three-Dimensional(3D)Heterogeneous Integration

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Journal of Semiconductors 2021年第2期42卷 1-2页

In the past few decades,the Moore’s Law has been the revolutionary force for our integrated circuit(IC)industry.However,the tremendous challenges faced in continuous transistor physical down-scaling and the unprecedented demands for computing and storage capabilities require our urgent search for strategies and solutions to integrate diverse materials,devices,circuits,and architectures in a 3D vertically stacked manner so that they can orchestrate in the most effective way to provide significantly enhanced functionalities as well as superior speed,energy,bandwidth,form fact,and cost.

关键词： Integration scaling integrate

Ti3AlC2-Al2O3/TiAl3复合材料在Al液中的熔蚀-磨损行为及其交互作用机制

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复合材料学报 2020年第10期37卷 2501-2511页

作者：肖华强赵思皓贵州大学机械工程学院贵阳550025

通过对比分析Ti3AlC2-Al2O3/TiAl3复合材料在纯腐蚀、纯磨损及熔蚀-磨损三种条件下的材料流失特征,研究了Ti3AlC2-Al2O3/TiAl3复合材料在Al液中的熔蚀-磨损行为及熔蚀与磨损的交互作用机制。结果表明,Ti3AlC2-Al2O3/TiAl3复合材料在Al... 详细信息

通过对比分析Ti3AlC2-Al2O3/TiAl3复合材料在纯腐蚀、纯磨损及熔蚀-磨损三种条件下的材料流失特征,研究了Ti3AlC2-Al2O3/TiAl3复合材料在Al液中的熔蚀-磨损行为及熔蚀与磨损的交互作用机制。结果表明,Ti3AlC2-Al2O3/TiAl3复合材料在Al液中的熔蚀-磨损体积损失比H13钢的体积损失低了两个数量级,随着载荷和转速的上升,Ti3AlC2-Al2O3/TiAl3复合材料的磨损由磨粒磨损逐渐向黏着磨损转变。Ti3AlC2-Al2O3/TiAl3复合材料的熔蚀、磨损交互作用率的最大值为47.5%,在低载荷或低转速条件下由于铝熔体的润滑作用,Ti3AlC2-Al2O3/TiAl3复合材料甚至表现出负的交互作用。这一方面是由于Ti3AlC2-Al2O3/TiAl3复合材料在Al液中腐蚀时不生成其它界面产物,而仅为极少量Ti元素的溶解;另一方面则是由于TiAl3基体与Al2O3二者所形成的空间网络状结构改善了Ti3AlC2-Al2O3/TiAl3复合材料在Al液中的耐磨损性能。

关键词：熔蚀-磨损 Ti3AlC2-Al2O3/TiAl3复合材料交互作用率 Al液

振动耦合场作用下低温原位合成Al_(3)Ti/Al-Mg-Mn复合材料的组织与力学性能

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材料工程 2023年第6期51卷 168-176页

作者：范滔林波林驰皓肖华强张卫文贵州大学机械工程学院贵阳550025 华南理工大学机械与汽车工程学院广州510640

通过超声和机械振动耦合场辅助,采用原位反应法制备了Al_(3)Ti/Al-Mg-Mn复合材料,研究了反应温度和耦合场作用时间对其组织演变和室温力学性能的影响。结果表明:超声和机械振动耦合场可以促进原位反应的进行,分散细化Al_(3)Ti颗粒。经76... 详细信息

通过超声和机械振动耦合场辅助,采用原位反应法制备了Al_(3)Ti/Al-Mg-Mn复合材料,研究了反应温度和耦合场作用时间对其组织演变和室温力学性能的影响。结果表明:超声和机械振动耦合场可以促进原位反应的进行,分散细化Al_(3)Ti颗粒。经760℃耦合场处理10 min后,Al_(3)Ti/Al-Mg-Mn复合材料室温抗拉强度、屈服强度和伸长率分别为222,119 MPa和8.1%,相比于Al-Mg-Mn基体,室温抗拉强度和屈服强度分别提高了17.5%和25.2%,伸长率由8.7%降低至8.1%。室温力学性能的提升,主要归因于Al_(3)Ti增强相引起的细晶强化、载荷传递强化和热错配强化,其中热错配强化对于复合材料强度的提升贡献最大。

关键词：原位反应铝基复合材料耦合场 Al_(3)Ti增强相显微组织力学性能

Al含量及热处理对挤压铸造Mg-Al-Zn合金组织和性能的影响

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热加工工艺 2012年第24期41卷 234-236页

作者：任丽蓉肖华强贵州民族大学理学院贵州贵阳550025 华南理工大学机械与汽车工程学院广东广州510640

研究了Al含量及固溶时效(T6)处理对挤压铸造Mg-Al-Zn合金显微组织和力学性能的影响。结果表明,晶界上的β-Mg17Al12相的体积分数随Al含量的增加而增加,其形态由孤岛状分布向不连续网状分布变化。当Al含量为8%时,合金具有最好的综合力学... 详细信息

研究了Al含量及固溶时效(T6)处理对挤压铸造Mg-Al-Zn合金显微组织和力学性能的影响。结果表明,晶界上的β-Mg17Al12相的体积分数随Al含量的增加而增加,其形态由孤岛状分布向不连续网状分布变化。当Al含量为8%时,合金具有最好的综合力学性能,经400℃×12 h固溶+200℃×8 h时效处理后,其抗拉强度和断裂伸长率达到了262.49 MPa和8.46%,相对挤压铸造态分别提高了16.07%和11.02%。

关键词： Mg-Al-Zn合金挤压铸造热处理组织性能

Channel Estimation for SCM-OFDM Systems by Modified Kalman Filter

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Communications and Network 2013年第3期5卷 666-670页

作者： Tao Peng Yue xiao Shaoqian Li huaqiang Shu Eric Pierre Simon IEMN Lab TELICE Group University of Lille Lille France Nation Key Lab of Sci. and Techno. On Commun. University of Electronic Science and Technology of China Chengdu China

In this paper, the problem of channel estimation for superposition coded modulation-orthogonal frequency division multiplexing (SCM-OFDM) systems over frequency selective channels is investigated. Assuming that the path delays are known, a new channel estimator based on modified Kalman filter algorithms is introduced for the estimation of the multipath Rayleigh channel complex gains (CG). In the simulation, the mean square error (MSE) and bit-error-rate (BER) performances are given to verify the effectiveness of the Kalman estimation algorithms for SCM-OFDM systems.

关键词： Superposition Coded Modulation (SCM) Orthogonal Frequency Division Multiplexing (OFDM) Channel Estimation Kalman Filter

挤压铸造AZ81镁合金的凝固行为及固溶时效处理

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热加工工艺 2013年第15期42卷 29-31,35页

作者：任丽蓉肖华强贵州民族大学理学院贵州贵阳550025 华南理工大学机械与汽车工程学院广东广州510640

研究了挤压铸造AZ81镁合金的显微组织及力学性能,描述了合金在挤压铸造过程中的凝固行为,研究了热处理对合金显微组织和力学性能的影响。结果表明,挤压铸造AZ81镁合金的显微组织由α-Mg初晶和高度弥散的α-Mg+β-Mg17Al12二元共晶组织组... 详细信息

研究了挤压铸造AZ81镁合金的显微组织及力学性能,描述了合金在挤压铸造过程中的凝固行为,研究了热处理对合金显微组织和力学性能的影响。结果表明,挤压铸造AZ81镁合金的显微组织由α-Mg初晶和高度弥散的α-Mg+β-Mg17Al12二元共晶组织组成,α-Mg初晶的体积分数随远离模具表面而逐渐增加。合金经400℃×12 h固溶+200℃×8h时效处理后,合金的抗拉强度和断裂伸长率相对挤压铸造态分别提高了16.07%和11.02%。

关键词： AZ81镁合金挤压铸造凝固行为固溶时效