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Applications of Ultrasonics Based on Chemical Effects—Sonochemistry
Published in Dale Ensminger, Leonard J. Bond, Ultrasonics, 2011
Dale Ensminger, Leonard J. Bond
In a patent, Weinberg [70] described a system for etching metals rapidly and uniformly, using either chemical or electrolytic etching under the influence of ultrasound. A representative application and materials claimed are chemical milling of aluminum, titanium, beryllium, boron, nickel, and tungsten. The method consists of immersing the material to be etched in a rigid brittle material, such as glass, suspended in an ultrasonically activated tank of tap water. An example was given of increasing the rate of etching of 6061 A1-alloy masked by an acid resist in aqueous solutions of HNO3, HF, and HC1 from 0.0127 mm/min without ultrasound, to 0.0381 mm/min with ultrasound, accomplished without lateral undercutting of the resist edges. The etched surfaces were claimed to be smoother and flatter than those etched without ultrasound. It was proposed that ultrasound dispersed the surface sludge and hydrogen bubbles, which retard the attack during static etching. Electrolytic etching in the same solutions increased the rate of metal removal at 535 A/m2 current density from 0.00381 mm/min without ultrasound to 0.1143 mm/min with ultrasound. The gain was attributed to ultrasonic vibrations breaking the insulating barrier that forms at the metal/liquid interface during electrolytic etching. Etching a beryllium sheet with ultrasound in an etchant of 450 ml H3PO4, 26.5 ml H2SO4, and 53 g CrCO3 proceeded at 0.02286 mm/min, producing a surface finish rated at 0.20–0.41 μm roughness; without ultrasound, the rate was 5.08 μm/min and the roughness was 63–80 μm. Tungsten sheet could be etched electrolytically in a 10% NaOH solution to a depth of 889 μm in 10 minutes with ultrasound, but without ultrasound no metal was removed.
Chemical Machining (CHM)
Published in Gary F. Benedict, Nontraditional Manufacturing Processes, 2017
Chemical milling is defined as the process of chemically eroding material to produce “blind” details (pockets, channels, etc.) or to remove material from all surfaces of a part for the purpose of weight reduction. Three masking techniques can be employed with chemical milling. The most common is the cut-and-peel technique followed by photoresist masks and screen-printed masks (masking techniques will be discussed in detail in the section on parameters). Of course, when material is to be removed from all surfaces of a part, no mask is used.
Laser welding of fuselage panels from aluminum V-1579 and aluminum-lithium V-1481 alloys
Published in Welding International, 2022
A. A. Skupov, M. D. Panteleev, A. V. Shcherbakov, E. A. Shein, V. E. Belozor
The studies were carried out on sheet semi-finished products of aluminum alloy V-1579 (2 mm thick) and aluminum-lithium alloy V-1481 (1.5 mm thick) in the T (after quenching) and T1 (after quenching and artificial ageing) condition. Semi-finished products in condition T1 were used. For them, surface preparation methods were worked out in which there is no porosity in welded joints: for alloy V-1481 - chemical milling to a depth of at least 0.15 mm according to PI 1.2.616-2003, followed by scraping the edges immediately before welding; for alloy V-1579 - chemical etching for the option when welding is carried out no later than a day after surface preparation and etching with scraping of edges before welding in case of an increase in the gap (up to 5 days) between etching and welding operations. Wire grades SvAMg5, SvAMg61, Sv1201 and Sv1221 with a diameter of 2 mm were used as filler materials. Welding was carried out on a robotic laser hybrid welding system Laser Weld 8R60. The complex includes an ytterbium fiber laser with a power of up to 8 kW (radiation wavelength: 1070 nm), a KUKA KR 60 HA manipulator with a positioning accuracy of 0.05 mm, a welding arc power source with a maximum current of 500 A. It is possible to carry out laser welding with a filler material and without it and hybrid, combining laser and arc welding in a shielded gas environment with a consumable electrode. In this work, we investigated the process of laser welding using filler material.
Multipoint support technology for mirror milling of aircraft skins
Published in Materials and Manufacturing Processes, 2018
Yan Bao, Renke Kang, Zhigang Dong, Xianglong Zhu, Changrui Wang, Dongming Guo
For solving these issues, mirror milling system (MMS) is proposed for machining aircraft skins, which is currently applied in Airbus Company.[15,16] MMS includes two five-axis machines used on the two sides of a skin part moving synchronously. The first one performs the pocket milling, and the other support on the opposite side. The support head is usually a metallic sphere.[7,12,17,18] MMS gradually becomes the next-generation machining technology for aircraft skin, used to replace chemical milling.[14]