Light-weighting in aerospace component and system design

Complex thin-walled titanium alloy components play a key role in the aircraft, aerospace and marine industries, offering the advantages of reduced weight and increased thermal resistance. The geometrical complexity, dimensional accuracy and in-service properties are essential to fulfill the high-performance standards required in new transportation systems, which brings new challenges to titanium alloy forming technologies. Traditional forming processes, such as superplastic forming or hot pressing, cannot meet all demands of modern applications due to their limited properties, low productivity and high cost. This has encouraged industry and research groups to develop novel high-efficiency forming processes. Hot Gas Pressure Forming (HGPF) and hot stamping-quenching technologies have been developed for the manufacture of tubular and panel components, and are believed to be the cut-edge processes guaranteeing dimensional accuracy, microstructure and mechanical properties. This article intends to provide a critical review of high-efficiency titanium alloy forming processes, concentrating on latest investigations of controlling dimensional accuracy, microstructure and properties. The advantages and limitations of individual forming process are comprehensively analyzed, through which, future research trends of high-efficiency forming are identified including trends in process integration, processing window design, full cycle and multi-objective optimization. This review aims to provide a guide for researchers and process designers on the manufacture of thin-walled titanium alloy components whilst achieving high dimensional accuracy and satisfying performance properties with high efficiency and low cost.

High-efficiency forming processes for complex thin-walled titanium alloys components: State-of-the-art and Perspectives

A multi-station continuous hot stamping production line, the production line comprising a loading platform (2), a feeding robot (3), a pressure generator set (4, 9, 11), a conveying robot (5), quenching apparatuses (6, 12), a discharging robot (7), and a conveyor belt (8) arranged in sequence; the pressure generator set comprises a heating apparatus, a moulding apparatus, and at least one pressure generator for mounting said moulding apparatus, the heating apparatus being used for heating all or part of a preformed blank (1) to obtain a hot blank, the moulding apparatus being used for stamping and moulding the hot blank and constant pressure shaping, trimming, and punching same to obtain a hot stamped piece. The present production line can continuously implement rapid heating, stamping, constant pressure shaping, trimming, punching, and quenching, increasing heating efficiency, and avoiding a transportation process prior to stamping the hot blank; blanking a steel plate stamping piece at a high temperature avoids the cutting difficulties as a result of producing martensite tissue at room temperature, reducing the blanking force and obtaining a better blanking edge. Also disclosed is a multi-station continuous hot stamping method.

Multi-station continuous hot stamping production line and method

The invention discloses a current auxiliary heat forming device with flexible clamping adopted. The device comprises a hydraulic system, a gas pressure control system, an upper platform, an upper die, flexible clamping systems, steel and copper composite electrode plates, a lower die and a lower platform. The upper die and the lower die are arranged between the upper platform and the lower platform. The hydraulic system installed on the upper platform controls the upper die to move towards the lower die. The steel and copper composite electrode plates are arranged at the two ends of the lower die, panel blanks are placed on the steel and copper composite electrode plates, and the flexible clamping systems are arranged at the two ends of the panel blanks. Each flexible clamping system comprises a semi-closed structure with one end open and a flexible pipe. The gas pressure control system provides gas pressure for the flexible pipes, the pipes are expanded out from the opening ends, and then the panel blanks are pressed. The forming of panels can be achieved when the dies are under the normal temperature state, the heat loss of the dies in the heating process and the energy needed for heating the dies to the set temperature do not exist, the forming efficiency of metal-based composite materials, titanium alloy, magnesium alloy, aluminum lithium alloy and other material panels hard to deform can be improved, the energy source consumption is reduced, and a very good energy saving effect is achieved.

Current auxiliary heat forming device and method with flexible clamping adopted

The invention provides a heterogeneous material tailor-welded blank hot stamping forming device and method with a controllable temperature field, and relates to a hot stamping forming device and method. The heterogeneous material tailor-welded blank hot stamping forming device and method aim at solving the problems that the hot stamping forming effect of an existing heterogeneous material tailor-welded blank is poor and even hot stamping forming fails. The device is characterized in that two columns of blocking adjustable electrodes and two clamping electrodes are clamped on the upper end face and the lower end face of a heterogeneous material tailor-welded blank, two electrode insulating pressing blocks are arranged on the two columns of blocking adjustable electrodes respectively in a press-fitting mode, two electrode cross-over blocks are cushioned at the lower ends of the two clamping electrodes respectively, the outer end of each blocking adjustable electrode is connected with a thermoregulation rheostat, and the multiple thermoregulation rheostats and a heating power supply form an electrified loop through wires. The method includes the steps that the material of the heterogeneous material tailor-welded blank to be formed is selected; the heterogeneous material tailor-welded blank to be formed is clamped; the heterogeneous material tailor-welded blank to be formed is heated; the heated heterogeneous material tailor-welded blank is stamped. The device and method are used for hot stamping forming of the heterogeneous material tailor-welded blank.

Heterogeneous material tailor-welded blank hot stamping forming device and method with controllable temperature field

The invention discloses a current-assisted rapid hot forming device and method for long and thin high-strength-steel structural components, relates to the technical field of high-strength-steel hot forming, particularly relates to a current-assisted self-resistance heating forming device and method and solves the problems that existing rapid hot forming devices are complicated to energize and existing rapid hot forming methods are applied to materials of low melting points and low hardness. The device comprises a power supply, a die, a pair of sheet clamping electrodes, two cushion blocks and two insulating mica sheets, the power supply, the sheet clamping electrodes and a sheet to be formed form an energized loop, the sheet clamping electrodes and the rest part of the die are insulated, insulation is achieved through the high-temperature-resistant insulating mica sheets, and the sheet to be formed is not in contact with the die. The method comprises that joule resistance heat produced by a current passing the sheet is used for heating the sheet directly, and after the forming temperature is reached, the rapid in-situ stamping forming is conducted. The device and the method are used for manufacturing the high-strength-steel structural components for vehicles.

Current-assisted rapid hot forming device and method for long and thin high-strength-steel structural components

Current assisted superplastic forming combines electric heating technology and superplastic forming technology, and can overcome some shortcomings of traditional superplastic forming effectively, such as slow heating rate, large energy loss, low production efficiency, etc. Since formability of titanium alloy at room temperature is poor, current assisted superplastic forming is suitable for titanium alloy. This paper mainly introduces the application of current assisted superplastic forming in the field of titanium alloy, including forming technology of double-hemisphere structure and bellows.

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Dai Xiangxiang

Papers

Current-assisted rapid hot forming device and method for long and thin high-strength-steel structural components

Current assisted superplastic forming of titanium alloy