一种采用螺旋气流包裹约束水射流的水导激光加工装置

本实用新型涉及一种采用螺旋气流包裹约束水射流的水导激光加工装置，包括壳体、上座体和下座体，上座体和下座体均设于壳体中，且上座体和下座体之间形成液压腔，上座体中设有窗口透镜，下座体中设有喷嘴，且激光穿过窗口透镜并聚焦于喷嘴处，液压腔中的液体经由喷嘴喷出形成水射流，下座体中设有螺旋气流发生器，所述螺旋气流发生器内设有储气腔、螺旋气流发生腔和多个气体通道，螺旋气流发生腔设于储气腔中部，各个气体通道沿着圆周方向呈螺旋状分布且每个气体通道一端与所述螺旋气流发生腔相切、另一端与所述储气腔连通，水射流穿过所述螺旋气流发生腔。本实用新型可以产生螺旋气流包裹的水射流，能有效降低加工过程中环境空气对水射流的干扰

一种基于LIBS技术的航空发动机涂层叶片制孔装置

本实用新型涉及航空发动机涂层叶片加工领域，具体地说是一种基于LIBS技术的航空发动机涂层叶片制孔装置，包括水导激光发生装置、透镜、等离子体光谱信号采集系统和分析控制系统，其中水导激光发生装置产生的水导激光射在航空发动机涂层叶片的制孔点处，制孔点产生的光辐射经由透镜聚焦后射入等离子体光谱信号采集系统，并经所述等离子体光谱信号采集系统转换为电信号输入至分析控制系统，等离子体光谱信号采集系统和分析控制系统形成LIBS系统，且LIBS系统检测材料元素无响应时发出信号使所述水导激光发生装置停止加工。本实用新型可以精准确定打孔深度，有效避免发生背烧等问题，且提高了加工精度及加工效率，精简了加工设备

Research on thermal damage mechanism of K424 superalloy processed with water⁃jet guided laser

为研究水导激光技术加工K424高温合金的热损伤区规律,使用自主研发的水导激光加工系统对K424高温合金薄片进行打孔实验,采用旋切法进行钻孔,并在激光穿透材料后在孔壁继续旋转几圈去边缘毛刺。将切下的圆形工件进行镶嵌、打磨、抛光、腐蚀和清洗,使用Zeiss EVO 10扫描电镜观测工件上的热影响区情况与重铸层的厚度。实验结果发现,水导激光加工后工件边缘位置的晶粒无明显变化,不存在热影响区。重铸层的厚度在2&mu;m以上,但是分布不均匀,有的位置甚至不存在重铸层。分析后得出结论为水导激光的激光功率过高或脉宽时间过长等相关参数会导致材料内部产生多余的热量,如果这些热量过高会造成加工位置附近形成热影响区,并产生过多的熔渣使重铸层的厚度增加。同时,加工过程中会由于水柱变向回流或者熔渣较大导致排水不畅等因素,都会造成水射流的不稳定,使工件切口处的重铸层的厚度变的不均匀。根据上述结论提出了解决水射流不稳定的加工方法。</p

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^