Filler metal

About: Filler metal is a research topic. Over the lifetime, 11152 publications have been published within this topic receiving 86590 citations.

Refractory metal backing material for weld repair

Abstract: The present invention relates to a method for repairing components such as blades used in turbine engines. The method comprises the steps of placing a piece of refractory metal material over an area of the component to be repaired and depositing a repair filler metal material over the piece of refractory material in an amount sufficient to repair the component and welding the repair filler metal material in place. The refractory metal material may be selected from the group consisting of niobium, tantalum, molybdenum, tungsten, a metal having a melting point higher than the melting point of nickel, and alloys thereof and may be uncoated or coated.

Development of a plasma MIG welding system for aluminium

Abstract: A new coaxial plasma MIG welding system is developed for the purposes of improvement of weld bead, reduction of spatter and fume generation. Welding power sources of MIG and plasma, wire feeding equipment and a coaxial plasma MIG welding torch are described in detail. The metal transfer of plasma MIG welding in aluminium is observed and compared with that of pulsed MIG welding. Although one droplet per pulse is obtained by both processes, plasma MIG welding shows more smooth metal transfer than pulsed MIG welding. The result shows that spatter and fume generation are drastically reduced, and clean and good weld bead appearance is obtained by the new system.

A process for the diffusion welding of copper and stainless steel

Abstract: A process for the diffusion welding of copper and stainless steel, which comprises sandwiching a thin layer of at least one metal selected from the group consisting of Ni, Ni-base alloys, Cr, Ni-Cr, and Cr-Ni with little gas contents, as an insert metal, between the surfaces of copper and stainless steel to be bonded, and then diffusion welding the sandwich.

Bonding of alumina to metals with Ag-Cu-Zr brazing alloy

Abstract: In active metal brazing, the reactive element in the brazing alloy enhances the wettability of the brazing alloy on ceramics and causes strong bonding by the redox reaction [1, 2]. The joint quality is also a function of the interfacial microchemistry and microstructures, such as the species and the morphology of the reaction product formed at the ceramic=brazing alloy interface [3, 4]. Therefore, it is very important to characterize and understand the interfacial reaction and its product at the metal= ceramic interface. However, in active metal brazing, there are many possible reactions at the interface between the reactive element and the ceramic or brazing alloy together with the bonded metal. Because of these complex reactions, the interfacial reaction is difficult to control. There are many reports on metal-ceramic joining with Ti containing brazing alloy, but few attempts have been made in brazing of alumina to metal with Zr contained AgCu based filler metal nor investigations of the interfacial reaction. In this study, Zr was selected as an active element for the brazing alloy since it showed stronger work of adhesion (Wad) on Al2O3 ceramics and more negative G of oxide formation [5] than Ti. The interfacial reaction and the effect of the morphological change of the brazing on the joint strength are discussed here. Discs of 99.9% AE-Al2O3 (diameter 14.5 mm and thickness 5 mm) were brazed to Ni-Cr steel and copper (diameter 12 mm and thickness 8 mm) using three kinds of brazing alloys, Ag-28 wt % Cu ‡ 5 wt % Zr (BZR), BZR ‡ 5 wt % Sn (BZS) and BZR ‡ 5 wt % Al (BZA). The brazing alloys were made by vacuum induction melting. Prior to brazing, all materials used were prepared in the same way as described elsewhere [6]. An elliptical radiant furnace equipped with a quartz tube was employed in the brazing experiment and it was evacuated to less than 10y5 torr (1 torr ˆ 133.322 Pa). Brazing was carried out in the temperature range of 750– 950 8C and the holding time was 30 min. A shear test was performed to evaluate the joint strength, and the microstructure and the interfacial reaction product were analysed using electron probe X-ray micro-analysis, EPMA, (JEOL JXA 840A) equipped with an energy dispersive X-ray spectroscopy EDS, (Link analytical LZ5) and glancing X-ray diffraction, XRD (Regaku Rotaflex RTP 300RE) and X-ray photoelectron spectroscopy, XPS (SSI 2830-S). Fig. 1 shows the SEM microstructure of (a) the interfacial structure and the concentration profile and (b) the reaction layer for Al2O3=Ni-Cr steel joint brazed at 950 8C for 30 min with Ag 28 wt % ‡ 5 wt % Zr brazing alloy. As depicted in Fig. 1b, the reaction layer consisted of Zr and small amounts of Al and Ag. The low Al content in the reaction product might be a result of the higher diffusivity of Al compared to that of oxygen in the molten brazing alloy and an unfavourable reaction to produce Zr-Al compound as compared with Zr-oxide. XRD analysis indicated that the reaction product was monoclinic ZrO2 (a ˆ 5:1463, b ˆ 5:2135, c ˆ 53110 A) even though EDS results showed the existence of Ag in the reaction product. However, Al2O3 is a more stable oxide thermodynamically in comparison with ZrO2 hence it is not feasible to form ZrO2 from zirconium and Al2O3. Simple equilibrium thermodynamics can not sufficiently characterize the interfacial reaction phenomena in the present brazing system. The Ag

Air-tight ceramic container

Abstract: A method of manufacturing an air-tight ceramic container is disclosed. This method includes the steps of coating an active metal consisting of Ti and/or Zr on an opening end face of a ceramic tubular member (1) in an amount of 0.1 to 10 mg/cm², thereby forming an active metal layer, placing a brazing filler metal on the active metal layer, placing a metal cover member (2) for shielding an opening portion of the ceramic tubular member (1) so that a peripheral portion end face of the metal cover member (1) is in contact with the brazing filler metal, and melting the brazing filler metal by heating, thereby brazing the metal cover member to the opening end face of the ceramic tubular member (1).