Investigating Nanoindentation Creep Behavior of Pulsed-TIG Welded Inconel 718 and Commercially Pure Titanium Using a Vanadium Interlayer

In a dissimilar welded joint between Ni base alloys and titanium, creep failure is a potential concern as it could threaten to undermine the integrity of the joint. In this research, the mechanical heterogeneity of a Pulsed TIG welded joint between commercially pure titanium (CpTi) and Inconel 718 (IN718) with a vanadium (V) interlayer was studied through a nanoindentation technique with respect to hardness, elastic modulus, and ambient temperature creep deformation across all regions (fusion zones and interfaces, mainly composed of a dendritic morphology). According to the experimental results, a nanohardness of approximately 10 GPa was observed at the V/IN718 interface, which was almost 70% higher than that at the V/CpTi interface. This happened due to the formation of intermetallic compounds (IMCs) (e.g., Ti2Ni, NiV3, NiTi) and a (Ti, V) solid solution at the V/IN718 and V/CpTi interfaces, respectively. In addition, nanohardness at the V/IN718 interface was inhomogeneous as compared to that at the V/CpTi interface. Creep deformation behavior at the IN718 side was relatively higher than that at different regions on the CpTi side. The decreased plastic deformation or creep effect of the IMCs could be attributed to their higher hardness value. Compared to the base metals (CpTi and IN718), the IMCs exhibited a strain hardening effect. The calculated values of the creep stress exponent were found in the range of 1.51–3.52 and 2.52–4.15 in the V/CpTi and V/IN718 interfaces, respectively. Furthermore, the results indicated that the creep mechanism could have been due to diffusional creep and dislocation climb.

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High Energy Shot Peening of Commercially Pure Titanium TIG Weld Joint

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.148-149.659 ◽

2010 ◽

Vol 148-149 ◽

pp. 659-663

Author(s):

Chun Huan Chen ◽

Rui Ming Ren

Keyword(s):

Surface Layer ◽

Weld Joint ◽

Shot Peening ◽

Welded Joint ◽

Pure Titanium ◽

High Energy ◽

Commercially Pure Titanium ◽

Nanostructured Surface ◽

Commercially Pure ◽

Cp Ti

Commercially pure Titanium (CP-Ti) TIG weld joint was treated by means of high energy shot peening (HESP) using a shot peening equipment commonly used in industry. The nanostructured surface layer was characterized by XRD, TEM, SEM and Microhardometer. The results showed that surface nanocrystallization of CP-Ti TIG weld joint were realized by high energy shot peening treatment. The finest grain size in the top surface layer is about 40nm. The hardness of the surface layer is enhanced significantly after shot peening compared with that of the as-welded joint, which resulted in a remarkable surface hardening effect. Surface welded defects such as air pores are eliminated successfully so that relative uniform surface layer was obtained.

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Dissimilar tungsten inert gas welding between Inconel 718 and commercially pure titanium using a vanadium interlayer

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/14644207211054265 ◽

2021 ◽

pp. 146442072110542

Author(s):

Tauheed Shehbaz ◽

Massab Junaid ◽

Fahd Nawaz Khan ◽

Usman Ali Akbar ◽

Abbas Saeed Hakeem

Keyword(s):

Intermetallic Compounds ◽

Inconel 718 ◽

Pure Titanium ◽

Interfacial Microstructure ◽

Optimization Approach ◽

Commercially Pure Titanium ◽

X Ray Diffraction ◽

Tungsten Inert Gas Welding ◽

Commercially Pure ◽

Aero Engines

A weight reduction of aero engines, in order to enhance their efficiency would be possible if the commercially pure titanium in the low-temperature region of the compressor could be welded with Inconel in the high-temperature portion. This joining of titanium/Inconel is challenging owing to the formation of hard TixNiy intermetallic compounds, the suppression of which is not possible using the conventional weld process optimization approach. In recent years, a number of approaches have been developed to reduce or eliminate these intermetallic compounds during welding and one approach is the use of an interlayer during the welding operation. The insertion of a V interlayer at the root side remarkably suppressed Ti and Ni diffusion across the interlayer. NiV3 and (Ti, V) solid solutions were present in the interfacial microstructure of V/Inconel 718 and V/commercially pure titanium, respectively, as characterized by scanning electron microscope and X-ray diffraction. The tensile strength of the weldment was 190 MPa (approx. 59% of the commercially pure titanium base metal) with an elastic modulus comparable with that of the base alloys. The joint exhibited brittle fracture at the Inconel 718 side near the V/Inconel 718 interface due to intermetallic compounds.

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RMI 0.2% Pd

Alloy Digest ◽

10.31399/asm.ad.ti0074 ◽

1979 ◽

Vol 28 (12) ◽

Keyword(s):

Corrosion Resistance ◽

Crevice Corrosion ◽

Elevated Temperatures ◽

Pure Titanium ◽

Heat Treating ◽

Low Ph ◽

Commercially Pure Titanium ◽

Bend Strength ◽

Commercially Pure ◽

Minimum Yield

Abstract RMI 0.2% Pd is a grade of commercially pure titanium to which up to 0.2% palladium has been added. It has a guaranteed minimum yield strength of 40,000 psi with good ductility and formability. It is recommended for corrosion resistance in the chemical industry and other places where the environment is mildly reducing or varies between oxidizing and reducing. The alloy has improved resistance to crevice corrosion at low pH and elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-74. Producer or source: RMI Company.

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UPM CP TITANIUM GRADE 3 (UNS R50550)

Alloy Digest ◽

10.31399/asm.ad.ti0167 ◽

2020 ◽

Vol 69 (6) ◽

Keyword(s):

Corrosion Resistance ◽

Pure Titanium ◽

Heat Treating ◽

Commercially Pure Titanium ◽

Commercially Pure ◽

Continuous Service ◽

Pure Grade ◽

Grade 3 ◽

Titanium Grade ◽

Design Stress

Abstract UPM CP Titanium Grade 3 (UNS R50550) is an unalloyed commercially pure titanium that exhibits moderate strength (higher strength than that of Titanium Grade 2), along with excellent formability and corrosion resistance. It offers the highest ASME allowable design stress of any commercially pure grade of titanium, and can be used in continuous service up to 425 °C (800 °F) and in intermittent service up to 540 °C (1000 °F). This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-167. Producer or source: United Performance Metals.

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