The arc additive manufacturing technology is a new technology combining product design, software control, additive manufacturing and subtractive manufacturing. Wire arc additive manufacturing (WAAM) is highly respected for its advantages of low preparation cost, high deposition efficiency, and high material utilization rate in metal additive manufacturing; and because of its high heat input and relatively low forming accuracy There are certain limitations. Therefore, it is urgent to develop additive composite manufacturing technology that can not only ensure the forming efficiency, but also accurately control the heat, mass and force. The composite manufacturing of arc increasing and decreasing materials is very suitable for the processing of ribs or similar thin-walled walls, ribs and other members on large frame members, which can achieve the purposes of reducing manufacturing costs and improving production efficiency. In addition to the problems of additive manufacturing accuracy and stress control, the cutting problem of post-additive controlled shape subtractive manufacturing is different from traditional removal processing, and is also affected by the unevenness of the additive deposition surface, additive residual heat and residual stress. In order to solve the above problems, in recent years, a variety of composite manufacturing methods for increasing and decreasing materials to achieve high-speed and high-efficiency forming and precise shape control are emerging. This article reviews the current researches on the forming errors of additive manufacturing, stress and deformation control after additive, and cutting processing after additive, aiming to explore the feasibility of manufacturing temperature-reduced composites of metal component additive composite belts, and seek reasonable utilization Additive waste heat, on the premise of ensuring the best processing accuracy, pursues a new manufacturing process with less residual stress, good material micro-performance and higher productivity.
Additive manufacturing (AM) technology, also known as 3D printing technology, is a part-manufacturing technology that combines computer-aided design and rapid prototyping technology to stack and deposit materials layer by layer. Additive manufacturing of metal materials often uses high-energy beams such as arcs, lasers, and electron beams as heat sources, and the raw materials are generally silk or powder materials. With the gradual improvement of the performance, accuracy, manufacturing cost and other requirements of metal parts in key technical fields such as aerospace, energy and power, national defense and military industry, the moldless near-net forming technology of additive manufacturing has become a research focus at home and abroad. This technology has the advantages of short overall manufacturing cycle, high degree of flexibility, and easy realization of digitalization and intelligent manufacturing. Due to different heat sources, additive manufacturing technology has large differences in forming accuracy, deposition efficiency, and sensitivity to part complexity. Wire arc additive manufacturing (WAAM) usually uses arc inert gas shielded welding (MIG), tungsten inert gas shielded welding (TIG), plasma arc welding (PAW), etc. as the heat source. The forming path is stacked layer by layer until the entire part is nearly net shaped, as shown in Figure 1. Compared with other forms of additive manufacturing processes for metal materials, arc additive manufacturing has the advantages of high deposition efficiency, high material utilization rate, low manufacturing cost, less size restrictions on parts, and easy repair of parts. In addition, the arc-additive formed parts are composed of fully welded metal, with uniform chemical composition and high density, and are superior to castings in terms of mechanical properties. After proper tempering, they can be comparable to forgings, compared with integral forgings It has the advantages of high strength and good toughness. In the multi-layer stacking process, the parts undergo multiple heating and multiple quenching and tempering, which can eliminate the problems of difficult hardening, macrosegregation, inconsistency of strength and toughness in the length and diameter of large castings and forgings.
However, arc additive manufacturing has certain limitations due to its high heat input and relatively low molding accuracy. In order to solve the above-mentioned shortcomings, in recent years, a variety of process methods have been developed to achieve high-speed and high-efficiency forming and precise shape control . Reduced material manufacturing in composite manufacturing is usually carried out after the added component is cooled to room temperature, which not only increases the auxiliary time of the entire manufacturing process, reduces production efficiency, but also makes the component frequently heated-melted-cooled During the cycle of cutting and reheating, the internal material structure and mechanical properties of the component are unstable, which is not conducive to the control of the overall performance of the component. This paper investigates the research status of composite manufacturing methods and key technologies of additive and subtractive materials, the mechanism of metal subtractive cutting and the current status of hot cutting, aiming to explore the feasibility of implementing subtractive processing in the process of additive cooling, so that composite subtractive processing can be reasonable Use additive effects to achieve the best accuracy and performance.