Residual Stresses in Similar and Dissimilar Friction Stir Welds of AA5083 and AA6061

2019 ◽  
Vol 813 ◽  
pp. 147-152
Author(s):  
Hernán Gabriel Svoboda ◽  
Leonardo Nicolás Tufaro ◽  
Francisco Javier Belzunce Varela
Keyword(s):  
Residual Stresses ◽  
Lattice Spacing ◽  
Transverse Direction ◽  
Welded Joint ◽  
Travel Speed ◽  
Tension Stress ◽  
X Ray Diffraction ◽  
Dissimilar Joints ◽  
X Ray ◽  
Friction Stir

Similar and dissimilar friction stir welds of AA5083 and AA6061 were produced modifying the location of the materials in the joint (advancing or retreating side) and travel speed (73 and 206 mm/min). Longitudinal and transverse residual stresses were evaluated by X-ray diffraction technique on the mid-length of each welded sample, in the transverse direction to the weld on a 42 mm distance. Unstrained lattice spacing (d0) and full width at half maximum (FWHM) were also measured. A peak of tension stress at the edge of stirred zone was detected, describing an “M” like profile, which were more asymmetrical for dissimilar joints. Variations in d0 and FWHM were also observed through the welded joint, which were related to microestructural changes.

scholarly journals The Effect of Specimen Size on Residual Stresses in Friction Stir Welded Aluminum Components

2014 ◽  
Vol 996 ◽  
pp. 445-450 ◽  
Author(s):  
Wulf Pfeiffer ◽  
Eduard Reisacher ◽  
Michael Windisch ◽  
Markus Kahnert
Keyword(s):  
Residual Stresses ◽  
Specimen Size ◽  
Hole Drilling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Friction Stir ◽  
Metal Parts ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method

Friction stir welding (FSW) is a well-known technique which allows joining of metal parts without severe distortion. Because FSW involves less heat input relative to conventional welding, it may be assumed that cutting specimens from larger friction stir welded components results in a negligible redistribution of residual stresses. The aim of the investigations was to verify these assumptions for a welded aluminum plate and a circumferentially-welded aluminum cylinder. Strain gage measurements, X-ray diffraction and the incremental hole drilling method were used.

scholarly journals X-Ray Diffraction Technique for Residual Stress Measurement in NiCrMo Alloy Weld Metal

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Vladimir Ivanovitch Monine ◽  
João da Cruz Payão Filho ◽  
Rodrigo Stohler Gonzaga ◽  
Elisa Kimus Dias Passos ◽  
Joaquim Teixeira de Assis
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welded Joint ◽  
Stress Measurement ◽  
Steel Wire ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wire Brushing ◽  
Alloy Weld

In the present work, residual stresses in nickel-based (Ni 625) superalloy weld metal of a 9%Ni steel-welded joint were measured by X-ray diffraction (XRD). This technique presents some difficulties in performing measurements in coarse and preferentially oriented weld metal microstructures. It is proposed a preliminary surface treatment by rotating steel wire brushing to perform the stress analysis through XRD technique possible for this kind of material. Stress measurements with proposed XRD technique showed that the stress state in Ni 625 weld metal on the outside surface of the welded joint is characterised by tensile stresses in the transverse and longitudinal directions, while compressive transverse and tensile longitudinal residual stresses are developed in the root pass region.

XRD Study on D-Values of Modified PbTiO3 Ceramics during Poling Process

2010 ◽  
Vol 177 ◽  
pp. 37-40
Author(s):  
Yuan Wei Zhang ◽  
X.G. Tang ◽  
A.X. Kuang ◽  
H.L.W. Chan
Keyword(s):  
Residual Stresses ◽  
Lattice Spacing ◽  
Mathematic Model ◽  
X Ray Diffraction ◽  
Poling Field ◽  
X Ray ◽  
Xrd Study ◽  
Domain Switch ◽  
D Values ◽  
Pbtio3 Ceramics

The Calcium modified PbTiO3 ceramics with large piezoelectric anisotropy was poled in consecutive steps. X-ray diffraction (XRD) found that the values of inter-planar spacing, d002 and d200, increased with poling field at initial poling stages. A noticeable drop of the d¬002 and d200 at the coercive field was observed. The residual stresses measured by the  angle tilt method were introduced. The relations of d002-sin2ψ and d¬¬200-sin2ψ at different poling stages were simulated by a mathematic model. The linear terms in the model are related to the macro-stress which may cause an elastic deformation; the exponential term in the model is related to the micro-stress which may cause a plastic deformation by the 90o domain switch. The results show that macro-stress and micro-stress decreased and the decay speed along  angle increased as to the d002 lattice spacing. The residual stresses related to the d200 lattice spacing were almost not changed.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals X-ray diffraction analysis of the structure and residual stresses of W/Cu multilayers

2006 ◽  
Vol 201 (7) ◽  
pp. 4372-4376 ◽  
Author(s):  
B. Girault ◽  
P. Villain ◽  
E. Le Bourhis ◽  
P. Goudeau ◽  
P.-O. Renault
Keyword(s):  
Residual Stresses ◽  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Grazing-incidence X-ray diffraction of single GaAs nanowires at locations defined by focused ion beams

2013 ◽  
Vol 46 (4) ◽  
pp. 887-892 ◽  
Author(s):  
Genziana Bussone ◽  
Rüdiger Schott ◽  
Andreas Biermanns ◽  
Anton Davydok ◽  
Dirk Reuter ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Lattice Spacing ◽  
Molecular Beam ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Ion Beams ◽  
Focused Ion Beams ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Nanowires

Grazing-incidence X-ray diffraction measurements on single GaAs nanowires (NWs) grown on a (111)-oriented GaAs substrate by molecular beam epitaxy are reported. The positions of the NWs are intentionally determined by a direct implantation of Au with focused ion beams. This controlled arrangement in combination with a nanofocused X-ray beam allows the in-plane lattice parameter of single NWs to be probed, which is not possible for randomly grown NWs. Reciprocal space maps were collected at different heights along the NW to investigate the crystal structure. Simultaneously, substrate areas with different distances from the Au-implantation spots below the NWs were probed. Around the NWs, the data revealed a 0.4% decrease in the lattice spacing in the substrate compared with the expected unstrained value. This suggests the presence of a compressed region due to Au implantation.

Investigation of Residual Stress/Strain and Texture in a Large Dissimilar Metal Weld Using Synchrotron Radiation and Neutrons

2013 ◽  
Vol 772 ◽  
pp. 193-199 ◽  
Author(s):  
Carsten Ohms ◽  
Rene V. Martins
Keyword(s):  
Synchrotron Radiation ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Large Scale ◽  
High Energy ◽  
X Ray Diffraction ◽  
Butt Weld ◽  
X Ray ◽  
Component Size ◽  
Thin Slice

Bi-metallic piping welds are frequently used in light water nuclear reactors to connect ferritic steel pressure vessel nozzles to austenitic stainless steel primary cooling piping systems. An important aspect for the integrity of such welds is the presence of residual stresses. Measurement of these residual stresses presents a considerable challenge because of the component size and because of the material heterogeneity in the weld regions. The specimen investigated here was a thin slice cut from a full-scale bi-metallic piping weld mock-up. A similar mock-up had previously been investigated by neutron diffraction within a European research project called ADIMEW. However, at that time, due to the wall thickness of the pipe, stress and spatial resolution of the measurements were severely restricted. One aim of the present investigations by high energy synchrotron radiation and neutrons used on this thin slice was to determine whether such measurements would render a valid representation of the axial strains and stresses in the uncut large-scale structure. The advantage of the small specimen was, apart from the easier manipulation, the fact that measurement times facilitated a high density of measurements across large parts of the test piece in a reasonable time. Furthermore, the recording of complete diffraction patterns within the accessible diffraction angle range by synchrotron X-ray diffraction permitted mapping the texture variations. The strain and stress results obtained are presented and compared for the neutron and synchrotron X-ray diffraction measurements. A strong variation of the texture pole orientations is observed in the weld regions which could be attributed to individual weld torch passes. The effect of specimen rocking on the scatter of the diffraction data in the butt weld region is assessed during the neutron diffraction measurements.

Features of structure formation processes in AA2024 alloy joints formed by the friction stir welding with bobbin tool

2021 ◽  
Vol 23 (2) ◽  
pp. 98-115
Author(s):  
Alexey Ivanov ◽  
◽  
Valery Rubtsov ◽  
Andrey Chumaevskii ◽  
Kseniya Osipovich ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Structure Formation ◽  
Welded Joints ◽  
Heat Input ◽  
Welded Joint ◽  
Welding Process ◽  
Tool Material ◽  
Travel Speed ◽  
Material System ◽  
Friction Stir

Introduction. One of friction stir welding types is the bobbin friction stir welding (BFSW) process, which allows to obtain welded joints in various configurations without using a substrate and axial embedding force, as well as to reduce heat loss and temperature gradient across the welded material thickness. This makes the BFSW process effective for welding aluminum alloys, which properties are determined by their structural-phase state. According to research data, the temperature and strain rate of the welded material have some value intervals in which strong defect-free joints are formed. At the same time, much less attention has been paid to the mechanisms of structure formation in the BFSW process. Therefore, to solve the problem of obtaining defect-free and strong welded joints by BFSW, an extended understanding of the basic mechanisms of structure formation in the welding process is required. The aim of this work is to research the mechanisms of structure formation in welded joint of AA2024 alloy obtained by bobbin tool friction stir welding with variation of the welding speed. Results and discussion. Weld formation conditions during BFSW process are determined by heat input into a welded material, its fragmentation and plastic flow around the welding tool, which depend on the ratio of tool rotation speed and tool travel speed. Mechanisms of joint formation are based on a combination of equally important processes of adhesive interaction in “tool-material” system and extrusion of metal into the region behind the welding tool. Combined with heat dissipation conditions and the configuration of the “tool-material” system, this leads to material extrusion from a welded joint and its decompaction. This results in formation of extended defects. Increasing in tool travel speed reduce the specific heat input, but in case of extended joints welding an amount of heat released in joint increases because of specific heat removal conditions. As a result, the conditions of adhesion interaction and extrusion processes change, which leads either to the growth of existing defects or to the formation of new ones. Taking into account the complexity of mechanisms of structure formation in joint obtained by BFSW, an obtaining of defect-free joints implies a necessary usage of various nondestructive testing methods in combination with an adaptive control of technological parameters directly in course of a welding process.

Sign in / Sign up

Export Citation Format

Share Document