Papers by Keyword: Inconel Alloy

Abstract: Study of weld joints of nonferrous, Inconel 625 alloy sheets using a new generation disk laser as the green welding technology for the effective manufacturing were carried out, and the results are presented in this paper. Weld joints of the Inconel 625 alloy sheets 2,0 mm thick were welded by laser without an additional material at a flat position, using a high purity argon as the shielding gas. The influence of laser welding parameters on weld quality and mechanical properties of test joints was studied. The influence of welding speed and laser power to the joint quality was investigated. The study of quality and mechanical properties of the joints were determined by metallographic evaluation, tensile and hardness tests.

Abstract: Abrasive flow machining (AFM) is one of the most promising technologies for internal finishing and de-burring for features with complex geometry. This study investigates the effect of media degradation on finishing characteristics achieved using the AFM process. A total of 50 experiments, using Inconel 718 cylindrical coupons machined by Wire-Electron Discharge Machining (WEDM), were conducted employing the same process conditions while using a single batch of AFM media. Experimental results indicate that media degradation has minor influence on surface roughness, but more significant influence on material removal and media flow rate. Material removal decreases exponentially with increasing cumulative media flow volume despite media flow rate increasing. There is a linear correlation between material removal and media flow rate. As a result, material removal can be estimated from media flow rate which can be monitored easily.

Abstract: The present work examines pore formation on type 316 stainless steel, Inconel 600 alloy and Co-Cr alloy. Ordered pore arrays are formed on the metallic substrates by electrochemical treatments in organic solvents containing perchlorate ions under optimized conditions. It is revealed that the key to form pore arrays is to control electrolyte composition. The formation of ordered pore arrays on stainless steel can be useful as the surface modification of the metallic biomaterial as the presence of pore arrays on stainless steel can enhance biocompatibility.

Abstract: Joining nickel based superalloys to gamma-TiAl intermetallic alloys will contribute to a more efficient application of these advanced materials, particularly in extreme environments. In this study, Inconel alloy and gamma-TiAl are joined using as filler alternated nanolayer thin films deposited onto each base material. The nanolayers consisted in Ni/Al exothermic reactive multilayer thin films with periods of 5 and 14 nm deposited by d.c. magnetron sputtering in order to improve the adhesion to the substrates and to avoid the reaction between Ni and Al. Diffusion bonding experiments with multilayer coated alloys were performed under vacuum at 800°C by applying 50 MPa during 1h. Bonding was achieved in large areas of the centre of the joints where regions without cracks or pores were produced, especially when using multilayer thin films with a 14 nm modulation period.

Abstract: Inconel alloy such as alloy 600 and alloy 690 is widely used as the steam generator tube materials in the nuclear power plants. The impact fretting wear tests were performed to investigate wear mechanism between tube alloy and 409 stainless steel tube support plates in the simulated steam generator operating conditions, pressure of 15MPa, high temperature water of 290°C and low dissolved oxygen(<10 ppb). From investigation of wear test specimens by the SEM and EDS analysis, hammer imprint, which is known to be an actual damaged wear pattern, has been observed on the worn surface, and fretting wear mechanism was investigated. Wear progression of impact-fretting wear also has been examined. It was observed that titanium rich phase contributes to the formation of voids and cracks in sub-layer of fretting wear damage by impact fretting wear.

Abstract: Laser welding process is widely used in the industrial field due to its numerous advantages: a small heat affected zone(HAZ), deep penetration, high welding speed, ease of automation, single-pass thick section capability, enhanced design flexibility, and small distortion after welding. In this paper, the laser weldability of Austenite stainless steel and INCONEL600 at dissimilar metal welds using a continuous wave Nd:YAG laser are experimentally investigated. INCONEL600 is being used in a steam generator tubing of pressurized water reactor(PWR) exposed to some corrosion. Therefore stress corrosion cracking can occur on this material. A research work is conducted to determine effects of welding parameters, on eliminating or reducing the extent welding zone formation at dissimilar metal welds and to optimize those parameters that have the most influence parameters such as focus length, laser power and welding speed were tested.

Abstract: A newly developed freeform fabrication process named 3D Micro-Welding, which is a combined system of a micro-TIG welding and a layered manufacturing method, is demonstrated. Various refractory alloys such as Inconel, stainless steel, and Invar can be freeformed besides elemental metals like titanium. Small metal beads of ~1mm in diameter are formed by emitting micro arc to the top of a thin metal wire of 0.2mm diameter. A fused bead is welded to a metal substrate or previously formed beads. By continuing this process and building up beads layer by layer under the control of CAD/CAM system, 3D objects were produced. In this study, optimization of micro-welding parameters such as the waveform of pulsed arc current and electrode materials were investigated and simple 3D objects of Inconel 600, SUS 304, Invar 42 were formed. The interfaces between adjacent beads were joined well and no crack or pore existed in the formed objects. The density and Vickers hardness of Inconel 600 objects showed comparable values to the commercial Inconel alloy, however the yield strength and Young’s modulus was about 80% and 70% of that alloy, respectively.