Filler metal

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

Method for controlling and/or regulating a welding apparatus, and welding apparatus

Abstract: A method for controlling and/or regulating a welding apparatus with a welding wire, wherein after ignition of an electric arc, a cold metal transfer welding process is conducted. For creating more various possibilities for controlling heat introduction into the work piece and/or for introducing filler material, it is provided that during at least some short-circuit phases, polarity of the welding current I and/or the welding voltage U is switched, wherein the amplitude of the welding current I and/or the welding voltage U is adjusted to a defined value so that melting-through of the welding wire and the short-circuit bridge, respectively, is prevented. There is also a safe re-ignition of the electric arc when lifting the welding wire off the work piece. It is also possible to reignite the electric arc only by the welding current I and/or the welding voltage U without any auxiliary voltage, at the end of the short-circuit phase or at the beginning of the electric-arc phase.

The effect of N2 addition upon the MIG welding process of duplex steels

Abstract: This paper presents the results of a study on the weldability of a duplex stainless steel, Avesta 2205, carried out by GMAW (MIG) pulsed arc welding process. An AISI 2209 electrode (AWS A/SFA 5.9, ER2209) was used as filler metal. The study was focused on the N2 content in the shield gas, from 0% to 6.4%. Firstly, a microstructural characterization of the welds using scanning electron microscopy (MEB-EDX) was carried out. Also, in order to study the microstructural changes originated by the welding thermal cycles and the % content of the N2, the ferrite content in the weld pool and heat affected zone (HAZ) were determined. Vickers hardness, tensile and bending tests were performed to determine the mechanical properties of joints and hence the influence of N2 addition without decrease in the mechanical properties. Finally, the joints were examined for susceptibility to intergranular corrosion using the Standard ASTM 262 93, practice A. The optimal content of N2 in the shield gas is included between 3% and 5%, which attain to obtain a 94% base material UTS.

Vacuum-furnace brazing of C103 and Ti–6Al–4V with Ti–15Cu–15Ni filler-metal

Abstract: C103 and Ti–6Al–4V alloys joined by vacuum-furnace brazing using Ti–15Cu–15Ni (wt%) commercial filler-metal was investigated This study examines how brazing conditions affect the microstructural evolution and shear strength of the C103/TiCuNi/Ti–6Al–4V joint According to the microstructural observations, all the characteristic structures of the joint interface can be classified into seven categories, based on their morphology and chemical composition The microstructural morphology of each characteristic zone depends on the brazing time and the brazing temperature Excessive increasing the brazing time and the brazing temperature form the coarse acicular Widmanstatten structure in front of Ti–6Al–4V parent-metal and cause grain growth of Ti–6Al–4V alloy However, if the brazing time is too short or the brazing temperature is too low, the continuous intermetallic-layer consisting of intermetallic compounds, such as Ti 2 (Cu, Ni) and Ti 2 (Ni, Cu), will remain in the brazed joints after brazing Additionally, during brazing, the diffusion of molten liquid filler-metal and the dilution of parent-metals cause the composition of the filler-metal to deviate from the Ti–Cu–Ni eutectic into the hypoeutectic or hypereutectoid Therefore, the joint interface is anticipated to be comprised mostly of eutectic and/or eutectoid structures The fine hypoeutectic and hypereutectoid structures consisting of α-Ti, Ti 2 (Ni, Cu) and Ti 2 (Cu, Ni) are observed in the joint interface brazed at 960 °C for 15 min The maximum shear strength reaches 354 MPa under this brazing condition Further increasing the brazing time and/or raising the brazing temperature cause excessive growth of the Widmanstatten structure and the grain of Ti–6Al–4V alloy, which significantly deteriorate the shear strength of joint The high temperature shear strength of the C103/TiCuNi/Ti–6Al–4V joint was investigated to evaluate its limit service temperature Moreover, the overlap-length and the joint clearance investigations are also conducted to realize the relations between different brazing conditions and the joint performance