Pure copper/copper alloy has excellent thermal and electrical conductivity, which is an important industrial material. Laser powder bed fusion, which represents the laser additive manufacturing technology, has excellent design freedom and forming accuracy, and is the mainstream development direction of additive manufacturing. Compared with traditional processing and manufacturing technology, the laser powder bed fusion of pure copper/copper alloy can give better play to the excellent performance of copper, and has broad application prospects in the fields of high thermal conductivity/electrical conductivity such as electrical and electronic, automotive, aerospace and other fields. The current research status of laser powder bed fusion of laser high-reflective materials represented by pure copper/copper alloys, the important problems they face, and the analysis of corresponding solutions were reviewed in this paper. On this basis, combined with the team's experience in the laser powder bed fusion process of pure copper/copper alloy, it was pointed out that the use of blue, green and other short-wavelength lasers for the powder bed laser fusion of pure copper/copper alloy and other highly reflective materials is a future study hot spots and development directions.

激光选区熔化技术(简称SLM)近些年来发展迅速,已应用于航空航天、医疗、模具等诸多领域.首先综述了近几年SLM领域的在线检测、离线检测技术的进展,重点介绍了SLM的在线检测手段,如利用同轴/旁轴原位架构的高速CCD及红外成像装置获取SLM过程中丰富的可见光和红外信息,介绍了相关描述子提取方法,并研究描述子与SLM成形质量的相关性,另外,少部分学者基于声信号信息源、光电二极管进行了单熔道成形质量的分类识别检测.此外,还介绍了SLM的离线检测手段,除传统的材料测试分析方法外,显微CT和激光诱导击穿光谱学为SLM的缺陷三维表征和成分分析提供了高效新型的工具;在此基础上,进而重点综述了SLM的过程监测及反馈控制策略.其中,介绍了常见的机器学习模型(K均值聚类分析、支持向量机、深度置信网络、卷积神经网络等)及其在SLM过程统计描述子提取中的研究进展.还介绍了统计过程控制方法在SLM的特征量间和特征量与SLM成形质量间的关系分析及控制图生成方面的应用;最后,对SLM在线和离线检测研究进展进行了总结,并对其主要发展方向进行了展望.

Expandable convoluted tube technology is based on a special process on round tubing to make the tubing de-formed so as to it can smoothly reach the trouble formation through the borehole; then by hydraulic expansion recovery, workover and cementing are realized.This technology has been used in petroleum engineering a lot after its many years’ development, but due to the confinement of the diameter and technology, it has not been applied in geological prospecting with smaller diameter.This paper presents the study that is mainly based on?75mm small diameter quincuncial shape ex-pandable convoluted tube being made of KP02 seamless steel tube, expansive transformation parameters are obtained by simulation with ANSYS finite element software and indoor experiments, and the contrast and analysis are made on the ex-panding process.