Showing papers on "Filler metal published in 1999"

Numerical modeling of the transient liquid phase bonding process of Ni using Ni-B-Cr ternary filler metal

Abstract: A model of dissolution and isothermal solidification during the transient liquid phase (TLP) bonding process of nickel using Ni-15.2wt.%Cr-4.0wt.%B ternary filler metal is presented. The model combined thermodynamic calculation with Thermo-Calc software and diffusion analysis by a finite difference method. The model assumed diffusion-controlled transformation, and the equilibrium compositions at the solid-liquid interface were calculated using Thermo-Calc software. The interface velocity was determined from the mass balance of solutes diffusing into or out from the interface. When a Ni specimen with a 30 µm thick filler metal was kept at 1473 K for 3.6 ks, isothermal solidification was almost complete. On the other hand, when the specimen was kept at 1373 K for 3.6 ks, residual liquid remained in the bonding region. The solidification sequence of the residual liquid during the cooling stage was calculated by the Scheil simulation. The simulation showed that solidification of the residual liquid is completed with a ternary eutectic reaction, L→fcc+Ni3B+CrB. The calculated width of the eutectic region concurred with the experimental result.

Preliminary investigation on joining performance of SiCp-reinforced aluminium metal matrix composite (Al/SiCp–MMC) by vacuum brazing

Abstract: The present study has investigated the joining performance of SiC particulate reinforced aluminium metal matrix composite (Al/SiCp–MMC) by vacuum brazing process. After the joints brazed with Al–Si–Mg foil brazing filler metal at different brazing batches, both the mechanical properties and the microstructures of brazed joints were estimated. Moreover, the influence of SiCp size, SiCp volume percentage and the brazing parameters on bonding quality of the joints have also been discussed in detail. The results have revealed that the bonding quality either in SiCp/Al interface or in SiCp/SiCp interface belongs to weak bonding, and the results also show that under the same brazing parameters condition, the strength of brazed joints decreases along with increasing the SiCp volume percentage. In addition, the results also indicate that for a constant SiCp volume percentage the strength of brazed joints decreases when SiCp size increases. These results are very useful for the joining design of discontinuously reinforced metal matrix composites and further for the optimum design of composition of composites.

Welding system and method

Abstract: A welding system (10) which allows a single welding operator to perform quick, easy and high quality vertical welds comprises a welding fixture (12) with a pair of opposing, positionally adjustable welding shoes, and lock screws for attaching to a workpiece (56) such as an I-beam. Welding fixture (12) is located adjacent the end of an articulating boom (20), and includes a welding torch (14) and oscillator (48). A rotary straight wire feeder (18) removes the cant and helix from welding wire as it is fed to the welding torch (14). The welding torch (14) prevents welding wire from fusing to a guide tube. A distributed welding control system comprising a plurality of controller modules (46, 48, 50, and 52) is interfaced with a common bus (54) and allows a welding operator to program automated welding cycles for various welding operations. The welding system (10) is particularly useful for installing stiffener plates (58) onto structural beams (56).

Method and apparatus for feeding welding wire

Abstract: A welding wire feeding system feeds welding wire from a barrel to a welding gun. The system includes a feed mechanism for drawing welding wire from the barrel and advancing the welding wire toward the welding gun. A free-wheeling wheel is disposed between the barrel and the feed mechanism and is freely rotatable about an axis. The welding wire is wound around the wheel, whereby a curvature is imparted to an otherwise-straight welding wire. Also, any twists generated in the welding wire at the welding gun will be stopped at the wheel before reaching and fouling the barrel.

The classification of metal weld deposits in terms of the amount of oxygen

Abstract: In analogy to the classification of metal weld deposits and arc welding processes of low-carbon and low-alloy steel in terms of the amount of hydrogen in metal weld deposits, a similar classification was given in terms of the amount of oxygen. Different methods of arc welding processes were chosen, such as welding with coated electrodes (basic, rutile, acid, oxide electrodes), shielded arc welding process MIG/MAG, submerged arc welding process (various wires, fluxes, shielded gases). The amount of oxygen and the percentage of acicular ferrite of metal weld deposits were mainly analysed and the impact toughness of it. Metallographical structures and fractography tests of metal weld deposit with varied amount of acicular ferrite were presented by putting attention to non-metallic inclusions and their morphology presented in metal weld deposit. Additional inclusions observation and measurements were done using a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. The studies were also made on the classification of metal weld deposits and arc welding processes of low carbon and low alloy steel in terms of the amount of oxygen in metal weld deposits on the following processes: low-oxygen processes, medium-oxygen processes, high-oxygen processes.

Laser welding superalloy articles

Abstract: A process is provided for laser welding a nickel or cobalt based superalloy article to minimize cracking by preheating the entire weld area to a ductile temperature, maintaining such temperature during welding and solidification of the weld, with the welding utilizing a powder alloy feed and the speed of the laser controlled to less than 10 inches per minute.

Analysis of mechanism of plasma and spatter in CO2 laser welding of galvanized steel

Abstract: In laser welding, quality, reproducibility and formability are required. That is the great problem in the automation of the laser welding process. Therefore, construction of an on-line process monitoring system of high accuracy is requested. The light which is emitted from plasma and spatter in laser welding was detected by photo-diodes. It was found that the light intensity depends on welding speed, laser power and flow rate of assist gas. The relationship between the plasma and spatter and the bead shape, and the mechanism of plasma and spatter were analyzed for on-line laser weld monitoring systems.

Microwave brazing process and brazing composition for tsp diamond

Abstract: A drill bit cutter is disclosed. The cutter comprises a thermally stable polycrystalline ('TSP') diamond, a tungsten carbide substrate, and a braze filler metal composition containing relatively large amounts of titanium. A method of brazing the TSP diamond to the substrate by microwave heating is also disclosed.

A Comparison of Gas Metal Arc Welding with Flux-Cored Wires and Solid Wires Using Shielding Gas

Abstract: In the present work, gas metal arc welding (GMAW) with flux-cored wires and solid wires using shielding gas has been adopted for welding stainless steel. Five different compositions of shielding gas are used with flux-cored wire and three with solid wire. Spatter rates, chemical compositions, tensile strength and elongation tests have been performed and are reported. The spotter rates of the sample made using flux-cored wires are less than that for the sample made using solid wire. The ultimate tensile strength and elongation are not influenced by the composition of the shielding gas.

Universal shielding gas for GMAW and FCAW welding and process

Abstract: A universal shielding gas mixture contains, by volume, about 96.0% argon, 3.0% carbon dioxide, and 1.0% oxygen. This single shielding gas composition can be used for welding ferrous metals, including both carbon steel and stainless steel using a variety of gas metal arc welding (GMAW) processes including short circuit arc, pulse arc, spray arc, metal transfer modes and flux core metal arc welding (FCAW) when welding carbon steel, stainless steel, hardfacing and metal core wires. This universal shielding gas composition will not substantially alter the carbon content of the weld metal chemistry. In a second embodiment, suitable for use with carbon steel materials but not stainless steel, the shielding gas mixture contains, by volume, about 95.0% argon, 3.0% carbon dioxide, and 2.0% oxygen. Another aspect of the invention is a single tank containing the premixed universal shielding gas, and improved gas metal arc welding processes that utilize the disclosed shielding gas mixture.

Weld bead characteristics in pulsed GMA welding of Al-Mg alloys

Abstract: The object of this investigation was to determine a suitable pulse parameter combination to obtain good-quality welds for a given weld bead size. Weld bead characteristics have been influenced by the parameters of pulsed current, i.e., peak current (I p ), peak duration (T p ), background current (I B ) and background duration (T B ). The effect of pulsed current parameters on gas metal arc (GMA) weld bead geometry was studied, and a single diagram in the nondimensional form was developed, representing many aspects of weld bead characteristics. This diagram was then used to select the most suitable combination of GMAW-P parameters for a given weld bead size in the welding of a 6-mm (0.236-in.) thick AA 5083 Al-Mg alloy base metal, using 1.2-mm (0.047 in.) diameter ER 5356 filler metal. The correlation of the cross-sectional area of penetration, total cross-sectional area of weld and nondimensional width of weld bead with operating parameter 'n' (a nondimensional heat input rate that governs the dimension of the weld pool) was obtained. Nondimensional terms were used to plot the results for all materials and welding variables on a single diagram, with many aspects of plate fusion behavior represented on a single graph.

Aluminum welding process and composition for use in same

Abstract: The invention provides a new and improved process and exothermic reaction mixture for producing molten weld metal. The molten weld metal is used in joining one metallic piece with at least one other metallic piece. The process and exothermic reaction mixture have distinct advantages over the prior art. These advantages include a higher filler metal yield, an increased tensile strength, and a higher quality corrosion resistant weld. These advantages are accomplished by a process wherein a reactant mixture is provided which has a reducing agent, a metallic compound, and at least two filler metals that at least in part do not chemically react with the metallic compound, one of which is aluminum. The metallic compound subsequently forms, with the reducing agent, having a high heat of formation which provides an exothermic reaction with sufficient heat to melt the filler metals. The reactant mixture is exothermically reacted to release heat and melt the filler metals and provide a flow of filler metals from the reactant and product mixture which may be contacted with objects to be welded by the filler metals.

Method and system for welding steel rails

Abstract: A method for gas shielded arc welding steel rails spaced from each other to define a transverse gap comprising the steps of positioning an elongated steel barrier plate in the gap at the bottom of the spaced rails and filling the gap above the barrier plate with a molten steel from an advancing filler metal electrode by a gas shielded electric arc welding process initiated by an arc between the electrode and the barrier plate. A root pass is laid using the spray arc welding process, a second layer is laid using the pulsed arc welding process in part and the spray welding process in part, and the remainder of the base gap and the gaps between the webs and heads are filled by the continuous sequential laying of weld beads in the gaps using the pulsed arc process. In filling the head gap, the electrode is first moved along rectangular paths to fill the transition portion of the gap and then along paths having laterally extending sides and catercorner path portions therebetween to fill the full width upper end of the head gap. Movement of the electrode is controlled to provide adjacent, overlapping beads which have first ends extending outwardly of an edge of the head in cantilever relationship thereto and which first ends are vertically thicker than second ends of the beads which are spaced from the first ends in the direction toward the opposite edge of the head.

Composite polycrystalline substance cutting tool and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To provide a composite polycrystalline substance cutting tool having a remarkably long tool life with respect to high speed cutting because of its high heat conductivity, and the manufacturing method thereof. SOLUTION: This composite polycrystalline substance cutting tool has a tool supporting body 4, and a composite polycrystalline substance material is formed on the tool supporting body 4 through a brazing filler metal 3. The composite polycrystalline substance material has a polycrystalline diamond layer 2 synthesized and grown by low pressure gas phase method, and a CBN sintered body 1 formed by extra-high pressure sintering, and the polycrystalline diamond layer 2 is arranged on the side of the tool supporting body 4.

Effects of niobium on microstructure, mechanical properties, and corrosion behaviour in weldments of alloy 690

Abstract: The present work investigates the effects of adding different quantities of Nb (0·1, 1·03, 2·49, and 3·35 wt-%) to the flux of electrodes used in welding Inconel alloy 690 on the microstructure, mechanical properties, and corrosion behaviour of the resulting weldments. Inconel filler metal I–52 coated with flux was used as the welding electrode. Weldments were butt welded using a manual shielded metal arc welding process. The experimental results indicated that the subgrain structure of the fusion zone was primarily dendritic. Niobium was depleted at the dendritic cores and enriched in the interdendritic regions. A small heat affected zone with typical coarse grains, which subsequently formed ghost grain boundaries, was present. With increasing Nb, the welds tended to show a finer subgrain structure and smaller dendritic spacing. Niobium rich segregants in the form of small particles formed in interdendritic spaces, providing the sites for microvoid formation by rupture. Correspondingly, the tensi...

Intermediate temperature joining of dissimilar metals

Abstract: Duplex stainless steel and silver-nickel-silver laminate were jointed to copper with a gold-germanium filler metal. Test joints were processed at, or below, 450 C (842 F) to assure meeting minimum base metal yield strength requirements. Creep and tensile properties of the bulk filler metal candidates, including a gold-indium alloy, were measured. A constitutive model, based on the Garofalo sinh equation, was developed from the creep data for use in predicting residual stresses in actual joints. Wetting behavior, interfacial reactions and joint microstructures were investigated, with samples processed in a vacuum between 400 to 550 C. Prototype joints were tested in shear. The Au-12 Ge filler metal offered the best alternative to the higher melting braze alloys. The alloy exhibited excellent wetting and creep behavior, with low contact angles, generally less than 20 deg, and good creep relaxation under typical loading conditions. As-fabricated shear test specimens yielded average joint strengths of 160 MPa (23 ksi).

Production of non-oxidation gas atmosphere fluxless brazing material and brazing method

Abstract: PROBLEM TO BE SOLVED: To eliminate a productivity hindrance factor resulting from coating/ drying of flux and to prevent lowering of brazability resulting from that water is introduced from a drying furnace to a brazing furnace in using a continuous furnace. SOLUTION: An aluminum material cladded with an Al-Si-Mg group alloy brazing filler metal containing a specified quantity of Mg and/or Bi, in a state of a coil or a flat cut sheet, is treated in an aqueous solution containing at least one kind of an inorganic acid selected from among nitric acid, surface acid, phosphoric acid and chromic acid in a total amount of 1-60 wt.% at 5-90 deg.C for 1 sec-20 min, an oxide film on a surface is removed up to . Successively, after a necessary working, before or after pre-assembly, it is heated to remove a forming oil and is brazed in non-oxidation gas atmosphere and fluxless.

Aluminum alloy clad material for heat exchanger, excellent in strength and corrosion resistance

Abstract: PROBLEM TO BE SOLVED: To provide an aluminum alloy clad material for a heat exchanger excellent in strength after brazing and corrosion resistance. SOLUTION: In a three-layer clad material of an aluminum alloy in which either face of a core is clad with a sacrificial anode material, and the other face of the core is clad with an Al-Si series alloy brazing filler metal, the core is composed of an aluminum alloy contg. 0.5 to 1.5% Mn, 0.2 to 0.6% Cu, 0.3 to 1.0% Si, 0.1 to 0.3% Mg, and the balance Al with impurities, and the sacrificial anode material is composed of an aluminum alloy contg. 0.3 to-.6% Mg, 0.5 to 2.5% Zn, 0.3 to 0.6% Si, and the balance Al with impurities. The thickness of the sacrificial anode material is preferably regulated to >=0.05 mm, and the content of Mg a impurities in the brazing filler metal is preferably regulated to <=0.03%. The aluminum alloy clad material can be suitably used as the header plate material of an automotive radiator in particular.

Aluminum alloy plate for super plastic forming, aluminum alloy tube and its super plastic formed body

Abstract: PROBLEM TO BE SOLVED: To obtain a wide width aluminum alloy plate for super plastic forming and to integrally form a large formed body by subjecting rolled plates of super plastic aluminum alloy each other to solid-state welding. SOLUTION: Solid-state welding is a joining method not remaining a solidified structure to a joining part. It is preferable for solid-state welding to use friction agitation welding, flash butt welding, DC butt welding, resistance welding. A super plastic aluminum alloy is either of Al-Mg alloy, Al-Zn-Mg alloy, Al-Zn-Mg- Cu alloy, Al-Cu alloy, Al-Li alloy, Al-Mg-Si alloy, Al-Si alloy, etc., a recrystallization grain is refined, a grain size is preferably =40% or softening annealing to a degree not generating recrsytallization in a process to produce a rolled plate.

Binder for aluminum brazing, flux or paint for applying flux and brazing filler metal, and aluminum brazing method

Abstract: PROBLEM TO BE SOLVED: To provide a paint which is less in risk of ignition or explosion, uniformly applied to a member formed of aluminum or aluminum alloy, and free from blocking between members by providing a binder appropriate in applying an aluminum (or aluminum alloy) brazing flux or a mixture of a flux with a brazing filler metal, and applying a brazing composition using the binder. SOLUTION: A methacrylic ester polymer in which the glass transition temperature is in a range of -30 deg.C to 60 deg.C, and the acid number in the dry condition is 20-80 is saponified with a compound showing cationic in aqueous solution to form an aqueous solution of binder of 1-50 wt.% in solid concentration. A paint for applying the flux contains the binder of 1-50 pts.wt., aluminate fluoride potassium flux of 50-100 pts.wt., and a specified alcohol of 1-50 pts.wt., and diluted with water to obtain solid concentration of 10-50 wt.%.

High-strength aluminum alloy clad material for heat exchanger excellent in tube manufacturing property and corrosion resistance

Abstract: PROBLEM TO BE SOLVED: To provide a high-strength aluminum alloy clad metal for a heat exchanger which is excellent in tube manufacturing property and corrosion resistance, and which is suitable for a material for a working fluid passage of the heat exchanger for an automobile including a radiator and a heater, and can be made thinner SOLUTION: Relating to the aluminum alloy clad metal that a sacrifice an anode is cladded on one surface of a core and an Al-Si brazing filler metal is cladded on the other surface, the core has the composition consisting of 06-20% Mn, 03-10% Cu, >=006% to <05% Si, 001-04% Fe, and the valance Al alloy consisting of Al with inevitable impurities, the sacrifice anode consists of aluminum alloy containing one or two or more kinds of 05-40% Zn, 0005-10% In, and 001-01% Sn, further containing 001-<05% Si and 001-05% Fe and the balance Al with inevitable impurities, the matrix of the core is of a fibrous structure, and the tensile strength of the clad metal is 170-260 MPa

Corrosion resistant aluminum alloy clad plate for vacuum brazing

Abstract: PROBLEM TO BE SOLVED: To provide a corrosion resistant aluminum alloy clad plate for vacuum brazing excellent in corrosion resistance and suitably usable as the core plate material of a drawn cup type heat exchanger. SOLUTION: This is a three layer clad plate of aluminum alloys for a drawn cup type heat exchanger in which either side of a core material is clad with a sacrificial anode material and the other side is clad with an Al-Si-Mg series brazing filler metal, and the core material is composed of an aluminum alloy contg. 0.3 to 1.8% Mn, >0.05 to 0.7% Cu, 0.05 to 0.5% Mg, 0.05 to 0.8% Si, 0.05 to 0.3% Ti, and the balance Al with impurities. The sacrificial anode material is composed of an aluminum alloy contg. one or more kinds among >0.5 to 1.8% Mn, >0.5 to 1.5% Mg and 0.1 to 1.0% Si, and the balance Al with impurities, and in which the content of Cu as the impurities is limited to <0.1%.