等离子切割工艺在低合金高强钢上的应用

从等离子切割的角度定义高强钢,详细阐述等离子切割工艺在高强钢上应用的适用特性。将等离子切割工艺与另外三种广泛应用的切割工艺进行对比,比较这些切割工艺对下道焊接工艺的影响。分析空气等离子切割工艺HAZ效果、切割质量和切割成本之间的关系,同时描述了高强钢等离子切割的设备要求即等离子切割电源、高度调节和CNC数控系统。     

水压缩弧等离子切割枪的研制与工艺试验

本文介绍了水压缩弧(以下简称水弧)等离子切割枪的工作原理及用此抢进行的各种切割工艺试验并将水弧等离子切割与普通气压缩等离子切割进行了比较。还介绍了应用水弧等离子切割和水净化工作台对改善劳动保护的效果。     

焊接与切割设备的使用和维修(六十八)——空气等离子弧切割机的使用与维修

讲述了250D空气等离子弧切割机的工作原理、故障现象、过程分析以及解决方法;介绍了影响等离子切割机使用效果的几个主要因素如工件材质、切割电流、空气压力和流量、喷嘴孔径、操作手法等,以及电极制造材料和消耗特性.最大限度地帮助焊工理解等离子切割常识,提高切割效果.     

等离子切割质量控制

在应用等离子切割的基础上,采用实验方法分析切割电流、切割速度、喷嘴高度和保护气体压力对切割质量的影响;总结等离子切割方法中切割电流、切割速度、喷嘴高度和保护气体压力对割缝质量的影响规律;分析切割材料、环境温度对等离子切割的影响,为等离子切割技术的推广与应用提供技术支撑。     

国内数控等离子弧切割技术的发展与应用

随着我国切割技术的迅速发展,数控等离子弧切割技术由于切割范围广、效率高、表面质量高而成为切割技术的主要发展方向。文中论述了我国等离子弧切割技术特点、研究与应用;综述了我国数控等离子弧切割技术的主要研究成果;分析了数控等离子弧切割技术主要问题和质量控制手段;展望了未来数控等离子弧切割技术的发展趋势。     

国内等离子切割的现状及发展趋势

随着国内制造业迅速发展,切割技术尤其是等离子切割技术也得到较快的发展。概述了等离子切割技术与气焰切割、激光切割的区别与联系,综合论述了等离子切割设备的现状及发展趋势,并分析了等离子切割方法的研究现状,最后总结了等离子切割技术存在的主要问题及以后开发的主要方向。     

多机并联的厚板等离子切割电源系统研究

通过数字化均流技术并联多台等离子切割电源,增大整套系统的切割电流,提高切割能力,进行厚板等离子切割。研究了一种大功率等离子切割电源系统,采用数字化处理芯片STM32F405RGT6为核心搭建等离子切割电源控制系统,实现等离子切割电源的全数字化控制。利用数字化平均电流算法,实现电源并联的均流控制,保证单台电源输出稳定均一电流。对研制的厚板等离子切割系统进行均流测试和厚板等离子切割试验。结果表明,所设计的等离子切割电源并联切割时电源工作稳定,电流均流分布,割缝质量较好。     

切割方式对直接淬火钢板的影响

研究了20 mm厚60 kg级直接淬火钢板不同切割方式下切割区域附近组织和硬度的特点。结果表明,火焰切割后,在割口附近会形成明显的软化区域,而等离子切割和激光切割无明显软化区域;等离子割口和激光割口处会重新淬火,其硬度远高于远离割口处;火焰切割割口的热影响区域大于等离子切割和激光切割。考虑到等离子切割和激光切割的适应厚度范围以及热影响区域的大小,推荐采用等离子切割20 mm厚60 kg级直接淬火钢板。     

数控等离子弧切割工艺

数控等离子弧切割是一种先进的热切割技术，结合所研制成功的数控火焰／等离子弧切割机分析了等离子弧切割工艺、切割工艺方法、工艺参数的选择及调整、切割后工件质量和常见的切割问题及产生原因。     

空气等离子切割

等离子切割通常采用双层气流等离子和空气等离子两种。双层气流等离子切割,具有保护切割喷咀的气体外罩(图1),可减少大气对切割气体的侵扰,从而切割速度更高,切口更平直。     

陶瓷刀具材料的种类与应用

陶瓷刀具材料是一种先进的切削刀具材料 ,由于其优良的切削性能和高的性能价格比而受到了人们的青睐。文中介绍了陶瓷刀具材料的的种类、牌号及其合理使用方法。     

Basic principles for the design of cutting edge roundings

Adapted cutting edge roundings lead to a performance increase of cutting tools. The optimal cutting edge design is determined by the thermomechanical process load and thus depends on the machined material. In this study, the external mechanical load is investigated in direct relation to material properties by means of microcinematography. It could be shown that load characteristics are mainly material independent, whereas the load level depends on the machined material. Finally, the findings were transferred into a model, which enables the design of cutting edge roundings based on material properties.     

Titanium machining with new plasma boronized cutting tools

Titanium is a commonly used material in various critical applications such as aerospace and biomedical applications. In this article, for the first time in the literature, development and implementation of a novel plasma boronizing process on Tungsten Carbide (WC) cutting tools is introduced. Plasma boronizing on WC tools is performed with gas combination of 10% BF₃, 40% Argon and 50% H₂ at different temperatures and durations. Performance enhancements of plasma boronized WC tools on Titanium (Ti-6Al-4V) machining are investigated under various cutting conditions. It is found that new plasma boronizing of WC is a very cost effective solution for significantly increasing tool life in Titanium machining.     

Cutting properties of water vapor plasma arc on 7A52 aluminum alloy plate

7A52 aluminum alloy was cut with an integrated equipment for welding and cutting using water vapor plasma arc. Various cutting mediums were tested. The arc force, electron density and cutting speed in each medium were tested and calculated. The fractography and microstructure of the cuts were also analyzed. Results show that the arc force, electron density and cutting speed increased with increasing acetone concentration. However, above a certain value (40%), higher acetone concentrations contribute little to the arc force and cutting speed. The microstructure of material near the cut was greatly influenced by the water vapor plasma arc. While the microstructure of the material beyond 10 mm from the cut was hardly influenced by the cutting heat. It was demonstrated that the water vapor plasma arc can be used for cutting of aluminum alloys in open field or emergency situations.     

芳纶纤维复合材料切削加工研究进展

随着芳纶纤维复合材料的应用日益广泛,不仅需要进行成形加工,还需要二次加工以保证后续精确配合、连接和装配的需要,这就对加工精度、效率和成本提出了相应要求。二次加工多用切削加工,易出现翻边、分层、拉毛、抽丝、烧焦等加工缺陷,限制了该材料的进一步应用。为拓展其用途,迫切需要全面展开芳纶纤维复合材料的二次加工技术研究。阐述了芳纶纤维复合材料的组成、结构、性能特点和应用领域,并以此为依据论证了芳纶纤维复合材料的切削性能,分析了加工缺陷产生的原因。综述了国内外芳纶纤维复合材料的二次加工现状,阐述了其加工机理和实验研究进展,包括芳纶纤维复合材料的典型加工工艺(如切削加工、铣磨、激光、超声、水射流等),以及对于切削力、表面质量、刀具磨损、切削变形、加工缺陷等方面的研究。切削加工是实现芳纶纤维复合材料二次加工的成熟、高效方法,迫切需要开展一系列切削机理和试验研究。     

影响材料切削加工性的各种因素探析

对影响材料的切削加工性的各种原因进行了分析,重点对工件材料的物理学性能、化学成分、金相组织等直接影响材料的切削加工性因素进行分析、对比。找出改善材料切削加工性的途径及方法。     

空气等离子切焊电源的调流方式

设计了空气等离子切焊机电源的调流方式；详细论述了集成芯片触发电路的连接调试等方面由于三相电源换相点等原因，晶闸管在等离子切焊设备中很难得到可靠地应用；论述了集成芯片触发电路在切焊设备中的应用是可行的。并且效果良好。     

Analysis of sheared edge formability of aluminum

Edge quality produced by shearing processes often leads to reduced material formability which was observed in multiple studies and summarized in the reference literature. The intention to make the sheared edge performance more predictable has motivated development of several experimental techniques such as the hole expansion test and the half dogbone tensile test. The paper presents a detailed review of published results for both of these techniques and illustrates very limited research dedicated to sheared edge performance of aluminum alloys. The experimental study, performed on a broadly used aluminum alloy, 6111-T4, illustrated the effects of cutting clearance on longitudinal, transverse and diagonal orientations of the trim line relative to the rolling direction. For all sheet orientations, increasing the cutting clearance resulted in a substantial reduction in material stretchability along the sheared surface. However, for all investigated conditions a cutting clearance of 5% of material thickness resulted in stretching performance similar to the standard tensile test. In this case the sheared edge does not affect the stretching behavior of tested material. The analysis of material prestrain on sheared surface stretchability for a variety of combinations of minor and major strains indicated that for the widely accepted industry standard gap of 10% of the material thickness, the prestrain has significant effects on stretchability which only gets stronger with increased thinning of the sheet in the prestraining process. For an extended clearance of 40%, the effect of prestrain was less visible indicating that the sheared edge has a stronger effect on these cutting conditions than prestrain.Analysis of the effect of the cutting angle on stretchability indicated that higher elongations were observed with cutting angles of 10° and 20° for broadly used 10% clearance compared to orthogonal cutting with an identical clearance.The results of half dogbone tensile tests were compared with the results of hole expansion tests performed on the same sheet material. This comparison indicated that a substantial amount of localization occurs in the hole expansion test and leads to a much higher hole expansion ratio for small cutting clearances compared to the total elongations observed in tensile tests. However, the local strains measured in the area adjacent to fracture in the tensile test were above the hole expansion ratio.     

Ti-Al系金属间化合物精密加工研究进展

稀有材料Ti-Al系金属间化合物的本征脆性在一定程度上限制了精密加工技术的选择和在航空航天、国防等领域的应用,为促进此类材料精密加工的适应性及获得高质量的表面,本文对Ti-Al系金属间化合物的精密加工技术进行综述。首先对此类材料的特性及精密加工技术进行总体概括;其次从材料的切削性能(材料去除机理、切削力、切削温度、切屑形态和刀具磨损)对其可加工性进行分析,并对材料加工后的表面完整性(表面粗糙度、表面缺陷、残余应力、加工硬化和金相组织)进行总结;最后,对应用于Ti-Al系金属间化合物所采用的超声振动辅助加工技术进行展望,以期为此类材料的加工提供一定的理论依据和技术支撑。