苗润 , 王伟力 , 宋杨 . TC4钛合金动态Ⅱ型裂纹扩展速度与加载速度的关系研究 [J ] . 兵工学报 , 2016 , 37 ( 12 ): 2331 - 2339 . DOI: 10.3969/j.issn.1000-1093.2016.12.020 http://doi.org/10.3969/j.issn.1000-1093.2016.12.020 为了确定TC4钛合金动态II型断裂实验中的起裂时间，计算TC4钛合金在发生II型断裂时塑性区能量吸收和裂纹扩展的速度，使用分离式霍普金森压杆装置对TC4钛合金进行动态II型 裂纹扩展实验。采用高速数字散斑相关方法获取观测点处位移-时间历程曲线，确定了动态II型 裂纹扩展的起裂时间，并计算出裂纹扩展速度。使用ABAQUS/Explicit软件建立有限元模型与实验结果进行同工况比对，在确认模型准确性后采用不同的加载速度研究II型加载条件下的裂纹扩展形式差异，计算出不同加载速度下的II型裂纹扩展速度，并得出加载速度与II型裂纹扩展速度的关系式。

MIAO R , WANG W L , SONG Y , et al. Research on relationship between crack propagation speed of TC4 alloy and loading speed under mode II dynamic loading [J ] . Acta Armamentarii , 2016 , 37 ( 12 ): 2331 - 2339 . (in Chinese) DOI: 10.3969/j.issn.1000-1093.2016.12.020 http://doi.org/10.3969/j.issn.1000-1093.2016.12.020 In order to ascertain the crack initiation time of TC4 in Mode II crack experiment, the energy absorption in plastic zone and the crack propagation speed are calculated. Split Hopkinson pressure bar (SHPB) is used to experiment upon Mode II crack propagation of TC4. High-speed digital speckle correlation method (HS-DSCM) is used to get displacement-time curve at a observation point, the Mode II crack initiation time of TC4 is determined, and the propagation speed of Mode II crack is calculated. A finite element model is established using ABAQUS/Explicit. The simulated results is compared to the experimental results. The propagation forms of crack at different impact velocities under loading condition are researched. Mode II crack propagation speeds at different loading speeds are calculated. Relation between loading speed and Mode II crack propagation speed is obtained.

黄竣皓 , 王琳 , 刘小品 , 等 . Ti-6321钛合金力学性能和抗弹性能 [J ] . 兵工学报 , 2021 , 42 ( 1 ): 124 - 132 .

HUANG J H , WANG L , LIU X P , et al. Mechanical properties and ballistic performance of Ti-6321 alloy [J ] . Acta Armamentarii , 2021 , 42 ( 1 ): 124 - 132 . (in Chinese) DOI: 10.3969/j.issn.1000-1093.2021.01.014 http://doi.org/10.3969/j.issn.1000-1093.2021.01.014 A series of mechanical experiments and ballistic performance tests were conducted on Ti-6321 titanium alloy with three microstructures of equiaxed, bimodal and Widmanstatten structures. The macro- and micro-damage characteristics of Ti-6321 targets were analyzed. The effects of microstructure and mechanical properties on ballistic performance of titanium alloy with different microstructures were investigated. The experimental results demonstrate that the equiaxed Ti-6321 targets exhibit the best ballistic performance and good mechanical properties. The dynamic mechanical properties, including dynamic flow stress and impact absorbing energy, exhibit a positive correlation with ballistic performance. Besides, the micro-damage analysis of the targets show that target with equiaxed structure has the least number, short lengths, and less bifurcations and convergences of adiabatic shear bands on it, while the target with Widmanstatten structure has the largest number, long lengths, and more bifurcations and convergences of adiabatic shear bands on it.

张川 , 张福隆 , 李跃峰 , 等 . 50CrV钢激光填丝焊焊缝成形多元非线性回归模型 [J ] . 兵工学报 , 2018 , 39 ( 11 ): 2256 - 2266 . DOI: 10.3969/j.issn.1000-1093.2018.11.021 http://doi.org/10.3969/j.issn.1000-1093.2018.11.021 在焊接50CrV薄板时，焊缝熔深要求控制在2 mm.为获得特定要求的熔深，基于响应面设计方法，采用实验设计软件Design-Expert 8.0对50CrV钢激光填丝焊焊接工艺进行了实验设计。实验过程中，以特定的焊缝熔深(2 mm)、最小化熔宽及余高为响应；以激光功率、焊接速度、送丝速度与离焦量作为控制变量，测量描述焊缝特征的响应数据，并建立其与焊接参数之间相关性的数学模型，通过方差检验确定了所建立的数学模型准确性。模型分析结果表明：激光功率、焊接速度、送丝速度与离焦量4个主因素对焊缝成形有直接的影响；根据优化结果得到最佳焊接条件，激光功率3.17～3.33 kW，焊接速度1.30～1.40 m/min，送丝速度4.0～4.23 m/min，离焦量3.1～4.5 mm，此时可获得满足焊接要求的熔深、熔宽和余高；实验验证了预测结果与实际焊接结果相一致，可用于指导实际生产。

ZHANG C , ZHANG F L , LI Y F , et al. Multivariate nonlinear regression analysis model of weld bead shaping of 50CrV steel by laser welding with filler wire [J ] . Acta Armamentarii , 2018 , 39 ( 11 ): 2256 - 2266 . (in Chinese) DOI: 10.3969/j.issn.1000-1093.2018.11.021 http://doi.org/10.3969/j.issn.1000-1093.2018.11.021 The weld penetration should be precisely controlled at 2 mm when welding 50CrV steel plates. The response surface design method is used to meet the requirement. The experimental design of laser filler wire welding process for 50CrV steel is made by using Design-Expert 8.0 software. During the experiment, the laser power, welding speed, wire feeding speed and defocusing distance are presumed as the welding process parameters, and the specific weld penetration (2 mm), minimized weld width and weld reinforcement are considered as the process responses. Weld bead measurements are carried out to generate the response dataset of describing weld characteristics, and the mathematical models correlating the process parameters with the responses are developed. The accuracy of the established mathematical model is determined by variance test. The result shows that the laser power, welding speed, wire feeding speed and defocusing distance have significant influence on the weld bead geometry. According to the optimizated results, the laser power of 3.17-3.33 kW, welding speed of 1.30-1.40 m/min, wire feeding speed of 4.0-4.23 m/min, and defocusing distance of 3.1-4.5 mm are identified as the optimal process parameters. Under these process conditions, the weld penetration, weld width and weld reinforcement meet the welding requirement. The verification experiment shows that the predicted results are consistent with the actual welding results. Key

徐楷昕 , 雷振 , 黄瑞生 , 等 . 40mm厚TC4钛合金窄间隙激光填丝焊接头组织及性能 [J ] . 材料导报 , 2022 , 36 ( 2 ): 162 - 167 .

XU K X , LEI Z , HUANG R S , et al. Microstructure and properties of 40mm-thick TC4 titanium alloy welded joint by narrow-gap laser welding with filler wire [J ] . Materials Reports , 2022 , 36 ( 2 ): 162 - 167 . (in Chinese)

FANG N W , GUO E J , HUANG R S , et al. Effect of welding heat input on microstructure and properties of TC4 titanium alloy ultra-narrow gap welded joint by laser welding with filler wire [J ] . Materials Research Express , 2021 , 8 ( 1 ): 016511 . DOI: 10.1088/2053-1591/abd4b3 http://doi.org/10.1088/2053-1591/abd4b3 A 10 mm narrow gap TC4 titanium alloy welded joint by laser welding with filler wire was obtained by different welding heat inputs. The microstructures of the welded joint were analyzed by OM, SEM, XRD and EBSD. The mechanical properties of the welded joint were analyzed by microhardness test and tensile test. The results show that with the increase of laser welding heat input, the average grain size and width of the equiaxed crystal zone in the center of the weld increases, the grain angle in the columnar crystal zone gradually tends to be perpendicular to the center of the weld, and the width of the heat affected zone (HAZ) increases without obvious grain coarsening. The HAZ of the welded joint is softened, and its microhardness value is lower than that of the weld and the base metal. The tensile strength of the welded joint is slightly higher than those of the base metal, but the elongation after fracture is less than that of the base metal, and it decreases with the increase of laser welding heat input.

石岩 , 刘佳 , 张宏 , 等 . 30CrMnSi钢激光焊接工艺研究 [J ] . 兵工学报 , 2010 , 31 ( 7 ): 991 - 997 . 为减小薄板30CrMnSi钢的焊接变形，提高焊接效率，采用CO₂激光对其进行了激光焊接工艺研究。采用激光显微镜、扫描电镜仪对微观组织进行了表征，采用显微硬度计、材料试验机等仪器对性能进行了测试。研究发现，激光焊接后的焊接接头分为焊缝区、热影响区、母材以及焊缝与热影响交界区和热影响与母材交界区5个部分。焊缝与热影响交界区显微硬度最高，母材显微硬度最低。焊接速度越快，焊缝的显微硬度越高，焊缝越窄。焊接速度越快焊接变形越小，激光功率4 kW、焊接速度8 m/min条件下，100 mm长度范围内的变形0.1 mm. 激光焊接接头的抗拉强度高于母材110～170 MPa，母材为韧性断裂，断口呈典型的韧窝形态，热影响区发生脆性断裂，断口呈准解理断裂，随着焊接功率和速度的提高，热影响区的拉伸强度有降低的趋势。

SHI Y , LIU J , ZHANG H , et al. Research on laser welding of 30CrMnSi steel [J ] . Acta Armamentarii , 2010 , 31 ( 7 ): 991 - 997 . (in Chinese) The laser welding technology of 30CrMnSi steel welded by CO₂ laser was studied in order to reduce its welding deformation and improve its welding efficiency. The microstructure, microhardness and tensile strength of the welding joint were systematically studied by means of SEM, microhardness tester as well as material testing machine. It is found that the welded joint is divided into five parts, such as welding seam zone, heat affected zone, matrix and interface zone between welding seam and heat affected zone, interface zone between matrix and heat affected zone. The microhardness increases from the center of welding joint to the two sides, and is maximized at the interface between the welding seam and heat affected zone. Then it begins to decrease fast at the interface between the heat affected and matrix zone. And the microhardness is minimized at the matrix. The faster the welding speed is, the higher the microhardness of welding seam is, and the narrower the width is. The deformation decreases with the increase in welding speed. The deformation within 100mm length is about 0.1 mm when the laser power is 4 kW and welding speed is 8m/min. The tensile strength of the welded joint is 110~170 MPa higher than matrix. The matrix bears a ductile fracture, and the fracture presents a dimple. A brittle fracture appears in the heat affected zone, and the quasi-cleavage fracture is presented. The tensile strength of the heat affected zone has a decrease tend with the increase in welding speed.

许良 , 苏居季 , 周松 , 等 . TC4钛合金激光双光束焊T形接头疲劳性能及断裂机理 [J ] . 中国有色金属学报 , 2019 , 27 ( 7 ): 1408 - 1416 .

XU L , SU J J , ZHOU S , et al. Fatigue performance and fracture mechanism of dual-beam laser T-joint of TC4 titanium alloy [J ] . Transactions of Nonferrous Metals Society of China , 2019 , 27 ( 7 ): 1408 - 1416 . (in Chinese)

徐楷昕 , 雷振 , 黄瑞生 , 等 . 摆动工艺对钛合金窄间隙激光填丝焊缝成形及气孔率的影响 [J ] . 中国激光 , 2021 , 48 ( 6 ): 143 - 151 .

XU K X , LEI Z , HUANG R S , et al. Effect of oscillation parameters on weld formation and porosity of titanium alloy narrow-gap laser wire filling welding [J ] . Chinese Journal of Lasers , 2021 , 48 ( 6 ): 143 - 151 . (in Chinese)

陈素明 , 赵安安 , 姜毅 , 等 . TC4钛合金激光填丝焊工艺参数对焊缝宏观成形的影响 [J ] . 中国激光 , 2021 , 48 ( 14 ): 74 - 80 .

CHEN S M , ZHAO A A , JIANG Y , et al. Influence of the technological parameters of TC4 titanium alloy laser wire filling welding on weld seam macroformation [J ] . Chinese Journal of Lasers , 2021 , 48 ( 14 ): 74 - 80 . (in Chinese)

孙燕洁 , 徐艳利 , 李瑞 , 等 . TC4钛合金薄板T形接头激光焊接工艺研究 [J ] . 航天制造技术 , 2010 ( 4 ): 19 - 23 .

SUN Y J , XU Y L , LI R , et al. Laser welding for T-joints of TC4 titanium alloy sheets [J ] . Aerospace Manufacturing Technologies , 2010 ( 4 ): 19 - 23 . (in Chinese)

郑昌鸿 , 张颖云 , 朱胜利 , 等 . 工艺因素对钛合金薄板激光焊接面外变形的影响 [J ] . 热加工工艺 , 2021 , 50 ( 9 ): 125 - 129 .

ZHENG C H , ZHANG Y Y , ZHU S L , et al. Influence of process parameters on out-of-plane deformation of titanium alloy thin plate laser welding [J ] . Hot Working Process , 2021 , 50 ( 9 ): 125 - 129 . (in Chinese)

姚君山 , 王国庆 , 刘欣 , 等 . 钛合金T形接头激光深熔焊温度场数值模拟 [J ] . 航天制造技术 , 2004 ( 2 ): 12 - 15 .

YAO J S , WANG G Q , LIU X , et al. Numerical simulation of the temperature field of laser deep fusion welding of titanium alloy T-joints [J ] . Aerospace Manufacturing Technologies , 2004 ( 2 ): 12 - 15 . (in Chinese)

黄亮 . TC4钛合金飞机壁板激光焊接工艺及残余应力研究 [D ] . 武汉 : 武汉理工大学 , 2014 .

HUANG L . The technology and residual stress analysis of laser welding of TC4 titanium alloy aircraft panel [D ] . Wuhan : Wuhan University of Technology , 2014 . (in Chinese)

FANG N W , GUO E J , HUANG R S , et al. Observation of grain growth and phase transformation in weld zone of Ti-6Al-4V titanium alloy by laser welding with filler wire [J ] . Materials Research Express , 2021 , 8 ( 5 ): 056507 . DOI: 10.1088/2053-1591/abfc7b http://doi.org/10.1088/2053-1591/abfc7b Through in situ observation at high temperature confocal laser scanning microscope, the microstructures and phase transformation of Ti-6Al-4V titanium alloy welded joint by laser welding with filler wire during heating, heat preservation and cooling process in simulating welding thermal cycle were studied. When the weld microstructure was heated to 380 °C, obvious grain growth was observed. After heating to 1 050 °C, weld microstructures were mostly composed of coarse β-columnar grains. During the heat preservation process of the weld metal, it could be found that the β phase boundary moved slowly. In the cooling process of weld microstructures, with the increase of the cooling rate, the transition temperature for new phase precipitation decreased gradually, and that for ending the precipitation increased gradually. The microstructures after cooling to room temperature at a rate of 0.5 °C/s and 5 °C s−1 were composed of α phases. At 20 °C s−1, acicular α′ martensite appeared in the microstructures. At 80 °C s−1, precipitated phases were all composed of acicular α′ martensite.The Ti-6Al-4V titanium alloy weld microstructure by laser welding with filler wire is completely hexagonal close packed (HCP) crystal structure.The hardness of the weld microstructures was improved with the cooling rate getting faster.

MA X Y , DUAN A Q , LU W , et al. Influence of heat input on welding processes weld formation microstructure and mechanical properties of double-sided laser beam welded Ti-6Al-4V alloy T-joints [J ] . Rare Metal Materials and Engineering , 2021 , 50 ( 7 ): 2300 - 2307 .

MOHANDA , SRINIVAS , KUTUMBARAO . Effect of post weld heat treatment on fracture toughness and fatigue crack growth behaviour of electron beam welds of atitanium (α+β) alloy [J ] . Fatigue & Fracture of Engineering Materials & Structures , 2010 , 23 ( 1 ): 33 - 38 .

何杨宇 , 杨素媛 , 包明明 , 等 . 激光焊接钛合金接头的组织演变和力学行为 [J ] . 稀有金属 , 2021 , 45 ( 8 ): 914 - 920 .

HE Y Y , YANG S Y , BAO M M , et al. Microstructure evolution and mechanical properties of titanium alloy plate [J ] . Chinese Journal of Rare Metals , 2021 , 45 ( 8 ): 914 - 920 . (in Chinese)

XU W F , MA J , LUO Y X , et al. Microstructure and high temperature mechanical properties of laser beam welded TC4/TA15 dissimilar titanium alloy joints [J ] . Transactions of Nonferrous Metals Society of China , 2020 , 30 ( 1 ): 160 - 170 . DOI: 10.1016/S1003-6326(19)65188-5 http://doi.org/10.1016/S1003-6326(19)65188-5 https://linkinghub.elsevier.com/retrieve/pii/S1003632619651885 https://linkinghub.elsevier.com/retrieve/pii/S1003632619651885

DUAN A Q , WANG Z S , PENG H , et al. Effect of undercut defect on deformation behavior TC4 titanium alloy laser welded butt joint under static tensile loading [J ] . China Welding , 2019 , 48 ( 8 ): 2432 - 2440 .

HOU J J , DONG J H , XU A P . Weld formation, microstructure and mechanical properties of laser welded TC4 titanium alloy with activating fluxes [J ] . Rare Metal Materials and Engineering , 2021 , 50 ( 12 ): 4236 - 4244 .