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Light(Advanced Manufacturing) 2024年第1期5卷 3-18页

作者： Huaping Tang Chaofeng Gao Shiheng Zhang Xiaojing Xiong Sheng Cao Xiaopeng Wu yunjie bi Jeremy Heng Rao Institute of Advanced Additive Manufacturing Ji Hua LaboratoryFoshanGuangdong528200China Department of Mechanical Engineering College of EngineeringShantou UniversityShantouGuangdong515063China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

The effects of direct aging treatment(at 300°C for 5 hours)on selective laser melted(SLMed)Al-4.5Mn-1.5Mg-0.9Sc-0.2Zr alloy were investigated in this work,with the microstructure,fatigue behaviors,and fracture characteristics examined to determine the primary cause of fatigue crack *** results revealed that the microstructure of the investigated alloy comprised fine equiaxed and columnar *** aging treatment,a significant number of nano-scaled Al3(Sc,Zr)precipitates were dispersed within the grains,leading to a substantial increase in *** yield strength improved from 431 MPa to 568 MPa,representing an increase of more than 32%,while the fatigue strength improved from 180 MPa to 220 MPa after aging ***,the fracture toughness decreased significantly from 25.1 MPa·√m to 12.3 MPa·√*** results of the fatigue fracture characteristics indicate that the Mn-rich phase and the formation of defects such as pores and poor powder fusion are the sources of fatigue *** direct aging treatment can significantly increase the yield strength,decrease the rate of fatigue crack propagation,and thus improve the fatigue performance,it deteriorates the fracture toughness,and thus shortens the fatigue life of the alloy as well.

关键词： Selective laser melting Al-Mn-Sc alloys High-cycle fatigue

Improved Removal Efficiency of Submicron Inclusions in Non-oriented Silicon Steel during RH Process

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Journal of Wuhan University of Technology(Materials Science) 2020年第6期35卷 1122-1127页

作者： CHEN Tianying JIN Yan CHENG Zhaoyang YUAN Zexi bi yunjie LIU Jing The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China

To improve the removal efficiency of such submicron inclusions,we designed an argon blowing method for an RH facility based on mathematical *** effect of the argon blowing on the liquid steel flow and the movement of submicron inclusions was studied using the k-ε flow model coupled with the DPM model for inclusion movement based on fluid computational dynamics in *** was found that a more uniform argon flow can be achieved in the up-leg snorkel with a new nozzle position and inner diameter,which resulted in a favorable up-lifting and mixing *** new design also increased the circulation rate of molten steel in the RH *** increased turbulent kinetic energy and turbulent dispersing rate enhanced the collision probability of submicron inclusions,which results in an improved removal for 0.5-1 μm *** proposed RH facility could increase the removal rate of submicron inclusions from the original 57.1% to 66.4%,which improves the magnetic properties of non-oriented silicon steel.

关键词： RH treatment argon blowing method model optimization submicron inclusions numerical simulation

Effects of direct aging treatment on microstructure,mechanical properties and residual stress of selective laser melted AlSi10Mg alloy

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Journal of Materials Science & Technology 2023年第8期139卷 198-209页

作者： Huaping Tang Chaofeng Gao Yong Zhang Nannan Zhang Chuan Lei yunjie bi Ping Tang Jeremy Heng Rao Institute of Advanced Additive Manufacturing Ji Hua LaboratoryFoshan 528200China Department of Materials Science and Engineering Monash UniversityClaytonVIC 3800Australia National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Hunan Farsoon High-Tech Co. LtdChangsha 410000China

Direct aging treatment is an important post-processing procedure,yet little research has been done on how it balances the mechanical properties and the stress removal for selective laser melted(SLMed)AlSi10Mg ***,we proposed a typical direct aging treatment on SLMed AlSi10Mg alloys,and studied the effects on their microstructure,properties and residual stress *** results indi-cate that the as-built microstructure is mainly composed of fine cellularα-Al and reticulated Si phases,and some pre-existing precipitates and dislocations are found in these *** direct aging treatment promotes the precipitation of nano-scaled Si phases and preserves a network-like Si ***,the strength of the peak-aged alloy increases while the ductility *** the aging temperature in-creases from 160 to 200℃,aging hardening behavior was accelerated *** at 160℃ for 4-9 h removes 32.0%-43.0%of the residual stress,which is attributed to the decomposition of the su-persaturatedα-Al matrix,the precipitation of the nano-Si phase and the exposure of low-angle grain boundaries(LAGBs).Considering the overal alloy performance obtained,over-aging at 160℃ for 4 h is the optimized heat treatment *** this condition,the yield strength(YS),ultimate tensile strength(UTS)and elongation(EL)of the alloy in the transverse and longitudinal direction are 309.5 MPa,464.4 MPa and 8.3%and 286.4 MPa,464.9 MPa and 5.1%,respectively.

关键词： Selective laser melting AlSi10Mg alloys Direct aging treatment Residual stress removal

Fatigue Cracking Characterization of High Grade Non-oriented Electrical Steels

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Journal of Wuhan University of Technology(Materials Science) 2017年第6期32卷 1329-1335页

作者：杜丽影周桂峰 LIU Jing SHI Wenmin bi yunjie CHENG Zhaoyang XUE Huan The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Wuhan 430081 China Wuhan Branch of Baosteel Central Research Institute (R&D Center of Wuhan Iron & Steel Co. Ltd.) Wuhan 430080 China

The fatigue behavior of 30 WGP1600 non-oriented electrical steel, which is generally used in the motors for electrical vehicles, was investigated. The detailed microstructure and dislocation configurations of the fatigue specimens were examined by OM, SEM, and TEM. The test results showed that fatigue cracks were commonly initiated from the surface grain boundaries, crystals plane, and inclusions. The rapid fatigue crack propagation was characterized by transgranular cleavage fracture, while most transient fracture exhibited ductile tearing characteristics. After cyclic deformation of the non-oriented electrical steels, various dislocation structures, such as short and thick lines, veins, persistent slip bands, cells, and labyrinth, were observed.

关键词： non-oriented electrical steel fatigue behavior crack initiation crack propagation dislocation structure

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活性气氛对金属材料激光增材制造的作用机制

中国激光 2022年第14期49卷 79-99页

作者：王大为董阳平田艳红毕云杰严明南方科技大学工学院材料科学与工程系广东深圳518055 哈尔滨工业大学先进焊接与连接国家重点实验室黑龙江哈尔滨150001 季华实验室广东佛山528200

激光增材制造(LAM)技术是智能制造的代表性技术之一,同时也是当前用于金属材料增材加工的主流技术。LAM成型的金属产品具有几何自由度大、尺寸精度高、质量和性能好等优势,已在航空航天、生物医疗、国防军事等行业中取得了广泛而重要的... 详细信息

激光增材制造(LAM)技术是智能制造的代表性技术之一,同时也是当前用于金属材料增材加工的主流技术。LAM成型的金属产品具有几何自由度大、尺寸精度高、质量和性能好等优势,已在航空航天、生物医疗、国防军事等行业中取得了广泛而重要的应用。LAM成型涉及以激光为热源的高温加热过程,因此通常需要对加工区域进行惰性气氛保护,避免空气对金属材料的污染。近几年来,利用N_(2)、Ar-O_(2)、Ar-N_(2)、Ar-CH_(4)等活性保护气氛的LAM技术快速兴起,在多种金属材料的力学性能提升方面取得了令人瞩目的成果,历史性地突破了气氛改性类技术难以影响材料内部的难题。同时,还涌现出在LAM加工前利用活性气氛改性打印原材料的新技术路径。本文针对活性气氛LAM这一颇具前景的新兴技术,阐述了国内外在近年取得的研究进展:从活性气氛保护的LAM加工与LAM原料活性气氛改性处理两大技术方向出发,归纳分析了这一新技术对钢铁、钛合金、铝合金、高熵合金等代表性金属材料的影响,系统比较了材料在力学性能等方面的提升、在组织与成型质量方面的变化,并详细揭示了其作用机理。同时,本文总结了活性气氛LAM技术面临的机遇和挑战,并对进一步明确气氛改性机理、扩展其应用范围提出了相应的展望。

关键词：激光技术高性能金属增材制造 3D打印活性气氛保护气体

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铝含量对IF钢热镀铝锌层组织和性能的影响

金属热处理 2020年第7期45卷 183-188页

作者：巩俐贾涓熊玮程朝阳毕云杰武汉科技大学省部共建耐火材料与冶金国家重点实验室湖北武汉430081

向热浸镀锌液中分别添加(质量分数)0.2%、1.0%、5.0%的Al,借助体视显微镜和SEM观察了IF钢表面镀层的微观结构,采用万能试验机进行三点弯曲试验,研究了不同Al含量对热浸镀镀层组织和性能的影响规律。结果表明,热镀铝锌镀层表面平整,存在... 详细信息

向热浸镀锌液中分别添加(质量分数)0.2%、1.0%、5.0%的Al,借助体视显微镜和SEM观察了IF钢表面镀层的微观结构,采用万能试验机进行三点弯曲试验,研究了不同Al含量对热浸镀镀层组织和性能的影响规律。结果表明,热镀铝锌镀层表面平整,存在网状沟槽,沟槽处为α(Al)+η(Zn)和Fe-Al-Zn金属间化合物。随着Al含量的增加,镀层表面龟甲块逐渐细小,镀层厚度逐渐增加。由于硬度高、脆性大,弯曲时裂纹从金属间化合物处发源,且随Al含量增多裂纹逐渐增多并平行排列。

关键词： Al含量热浸镀锌镀层结构 Fe-Al-Zn金属间化合物裂纹

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激光熔覆垂直及倾斜工况下粉末输运行为研究

激光与光电子学进展 2023年第13期60卷 211-221页

作者：赵豪杨季鑫胡晓圻王瑞毕云杰季华实验室新型增材制造研究院广东佛山528200

通过建立同轴喷嘴和粉末输运过程的数值模型,采用数值仿真模拟的方式研究了不同工艺参数下,同轴喷嘴在垂直和倾斜使用工况下粉末汇聚性的变化规律。结果表明:粉末聚焦处的粉末浓度随载粉气速度的增加而降低,而保护气速度对粉末浓度影响... 详细信息

通过建立同轴喷嘴和粉末输运过程的数值模型,采用数值仿真模拟的方式研究了不同工艺参数下,同轴喷嘴在垂直和倾斜使用工况下粉末汇聚性的变化规律。结果表明:粉末聚焦处的粉末浓度随载粉气速度的增加而降低,而保护气速度对粉末浓度影响较小;在载粉气流量为8 L/min,保护气流量为20 L/min,送粉量为15.8 g/min时,相比于同轴喷嘴垂直使用,倾斜使用条件下粉末的聚焦高度由19 mm升高到21 mm,焦点直径由3.7 mm增大到4.2 mm;同轴喷嘴垂直使用时粉末分布的均匀性更好;数值模拟结果与试验结果吻合良好,可以准确反映不同送粉方式中粉末的输运特性。

关键词：激光技术同轴喷嘴数值模拟粉末流场倾斜工况

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预应变对DP600钢氢脆敏感性的影响

中国腐蚀与防护学报 2018年第5期38卷 424-430页

作者：柯书忠刘静黄峰王贞毕云杰武汉科技大学省部共建耐火材料与冶金国家重点实验室武汉430081

利用慢应变速率拉伸实验(SSRT)及双电解池渗氢实验,结合断口形貌观察和分析,探索了预应变对DP600钢氢脆敏感性的影响规律及机理。结果表明:在本实验预应变量范围内,预应变量小于15%时,随着预应变量的增大,DP600钢试样的氢脆敏感性不断增... 详细信息

利用慢应变速率拉伸实验(SSRT)及双电解池渗氢实验,结合断口形貌观察和分析,探索了预应变对DP600钢氢脆敏感性的影响规律及机理。结果表明:在本实验预应变量范围内,预应变量小于15%时,随着预应变量的增大,DP600钢试样的氢脆敏感性不断增大,当预应变量达到15%以后,其氢脆敏感性基本趋于稳定。预应变增大了钢中的位错密度,使氢的有效扩散系数降低,有效捕获的氢量增加,从而使钢试样的氢脆敏感性增大;但当预应变量进一步增加至15%以上时,位错的相互缠结减缓氢的扩散和聚集速度,从而使试样的氢脆敏感性增加趋于平缓。

关键词： DP600钢预应变慢应变速率拉伸实验渗氢技术氢脆敏感性氢扩散

回火温度对DP600钢氢扩散及氢脆敏感性的影响

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金属热处理 2021年第2期46卷 87-94页

作者：王贞刘静黄峰毕云杰柯书忠武汉科技大学省部共建耐火材料与冶金国家重点实验室湖北武汉430081 武汉科技大学湖北省海洋工程材料及服役安全工程技术研究中心湖北武汉430081

利用慢应变速率拉伸和双电解池氢渗透试验,结合SEM、TEM、EBSD表征手段研究了不同回火温度下DP600钢中显微组织变化对其氢扩散及氢脆敏感性的影响。结果表明,DP600钢的氢脆敏感性和有效氢扩散系数均随回火温度的升高呈下降趋势,这主要... 详细信息

利用慢应变速率拉伸和双电解池氢渗透试验,结合SEM、TEM、EBSD表征手段研究了不同回火温度下DP600钢中显微组织变化对其氢扩散及氢脆敏感性的影响。结果表明,DP600钢的氢脆敏感性和有效氢扩散系数均随回火温度的升高呈下降趋势,这主要与钢中位错、小角度晶界等可逆氢陷阱浓度降低以及碳化物/基体界面、大角度晶界等不可逆氢陷阱浓度增加有关。其中弥散分布的碳化物使碳化物/基体界面捕获的氢原子分布均匀,导致试验钢的氢脆敏感指数由44.6%(270℃)下降至1.8%(350℃)。综合考虑回火温度对试验钢强度和氢脆敏感性的影响,DP600钢的最佳回火温度为330℃。

关键词： DP600钢回火温度氢扩散氢脆敏感性

热处理工艺对离心铸造高铬铸铁轧辊组织及硬度的影响

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金属热处理 2020年第2期45卷 108-113页

作者：曹宇宋新莉郑爱琴陈荣东贾涓毕云杰武汉科技大学耐火材料与冶金国家重点实验室武汉湖北430081

采用了光学显微镜、扫描电镜、X射线衍射仪、洛氏硬度计等仪器,研究了离心铸造高铬铸铁轧辊铸态及淬火与回火后的显微组织结构、碳化物和硬度等。结果表明:高铬铸铁轧辊铸态组织主要是由奥氏体+少量马氏体+(Cr,Fe)7C3碳化物组成,碳化物... 详细信息

采用了光学显微镜、扫描电镜、X射线衍射仪、洛氏硬度计等仪器,研究了离心铸造高铬铸铁轧辊铸态及淬火与回火后的显微组织结构、碳化物和硬度等。结果表明:高铬铸铁轧辊铸态组织主要是由奥氏体+少量马氏体+(Cr,Fe)7C3碳化物组成,碳化物呈粗大板条状或块状;不同温度热处理后,得到回火马氏体+(Cr,Fe)7C3+Cr7C3碳化物的组织,组织中粗大板条状碳化物消失,得到细小块状或椭圆状碳化物。该高铬铸铁轧辊铸态硬度为56. 0 HRC左右,在950℃淬火及400℃回火处理后硬度增加到了约65. 5 HRC。

关键词：高铬铸铁轧辊热处理碳化物硬度