Papers by Keyword: Inconel 718

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Authors: Guang Ming Zheng, Jun Zhao, Xin Yu Song, Xiang Cheng
Abstract: A 3D finite element model (FEM) of metal cutting was constructed based on the thermal-mechanical coupling theory. The cutting process of Sialon ceramic tools turning Inconel 718 was simulated and experimented. The effect of cutting speed, feed rate and depth of cut on the cutting force was analyzed. According to the correlation characteristics between the data points, the fractal characteristics of cutting forces in the cutting process were also investigated. The results showed that the cutting speed had a great effect on the fractal dimension of cutting force. The simulation results were in good agreement with the experimental findings. It was concluded that the minimum fractal dimension of cutting force was obtained at v=230 m/min under these experiment conditions. The fractal analysis is a simple and powerful tool for quantifying the stability of cutting process. The finding of this research is valuable for future practical implementation.
Authors: M. Vignesh, K. Venkatesan, R. Ramanujam, P. Kuppan
Abstract: Inconel 718, a nickel based alloys, addressed as difficult to cut material because of hard carbide particle, hardness, work hardening and low thermal conductivity. Improving the machinability characteristics of nickel based alloys is a major anxiety in aircraft, space vehicle and other manufacturing fields. This paper presents an experimental investigation in Laser assisted turning of Inconel 718 to determine the effects of laser cutting parameters on cutting temperature and cutting forces. This nickel alloy has a material hardness at 48 HRC and machined with TICN/Al2O3/TiN tool. This is employed for the manufacture of helicopter rotor blades and cryogenic storage tanks. The experiments were conducted at One-Factor-at-a-Time.The effects of laser cutting parameters, namely cutting speed, feed rate, laser power and laser to work piece angle, on the cutting temperature and cutting force components, are critically analysed and the results are compared with unassisted machining of this alloy. The experiments are conducted by varying the cutting speed at three levels (50, 75, 100 m/min), feed rate (0.05, 0.075 0.1 mm/rev), laser power (1.25 kW, 1.5 kW, 1.75 kW) and at two level laser to work piece angle (60, 75°). At the optimal parametric combinationof laser power 1.5 kW with cutting speed of 75m/min, feed rate of 0.075 mm/min and laser to work piece angle 60°, the benefit of LAM was shown by 18%, 25% and 24% decrease in feed force (Fx), thrust force (Fy) and cutting force (Fz) as compared to those of the conventional machining. Examination of the machined surface hardness profiles showed no change under LAM and conventional machining.
Authors: C.S. Ramesh, R. Suresh Kumar, G. Dilip Maruthi, Mohammed Faizan
Abstract: Al6061 has immense use in manufacture of several internal combustion engine parts as well. However the internal parts of an IC engine manufactured using Al6061 are susceptible to corrosion. Water may condense on the cylinder walls or move across the piston rings owing to blow-by and thus be admitted into the crankcase. This usually occurs in cold environment or short duration drive since pertaining to these conditions the engine may still be not hot enough to get rid of this water by evaporation. Upon amalgamation of this condensed water with the sulphur present in considerable quantities especially in low-grade fuels, sulphuric acid is formed thereby leading to a localized corrosion enhancing corrosive environment. In this work, TiO2 and Inconel 718 are plasma sprayed on Al6061 specimen and their ability to protect against corrosion is studied and observed that the corrosion resistance of specimen coated with TiO2 has improved by a considerable margin.
Authors: Huai Zhong Li, Jun Wang
Abstract: nconel 718 is one of the most commercially important superalloys but with very poor machinability. It has a very high yield stress and a high tendency to adhesion and work-hardening. A recent trend of improving the machining processes of difficult-to-cut materials is to move towards dry cutting operations. This paper presents an experimental study of the cutting forces in high speed dry milling of Inconel 718 using a milling cutter with coated carbide inserts. It is found that the peak cutting forces increase with an increase in chip load in a nonlinear way, but cutting speed does not show a significant influence on the cutting force for the range of cutting speeds tested in this study.
Authors: Hong Sun Park, Hyung Ick Kim, Yong Huh, Moon Young Kim, Sang Yeol Park, Jae Mean Koo, Chang Sung Seok
Abstract: The Ni-based superalloy Inconel 718 (IN-718) was developed in the 1950s and is currently used for several critical gas turbine components due to its good balance of mechanical properties. Because of its stable mechanical properties at high temperature, the alloy is used for turbine bolts. The mechanical properties of in-service facilities are required to maintain safety operation in power plants. Ultrasonic tests, tensile tests and hardness tests were performed to evaluate the degree of the material degradation of Inconel 718. The mechanical properties decreased as degraded, but the longitudinal velocity of the ultrasonic signal increased. Also, the microstructure of the degraded Inconel 718 was to study the relationship between the result from ultrasonic test and the results from destructive methods.
Authors: Chun Yao Hsu, Chung Chen Tsao, C.H. Huang, Yu Cheng Lin
Abstract: Increasing the productivity and the quality of the machined parts are the main challenges of manufacturing industry, in particular for difficult-to-machine materials, such as Inconel 718, employed in aeronautic and aerospace applications. A L18 (2×37) orthogonal array (OA) and signal-to-noise (S/N) were employed to analyze the effect of mill parameters when milling Inconel 718. Experimental results indicated that the cutting tool, depth of cut, cutting speed, feed rate, frequency and coolant have statistical and physical significance on the flank wear, surface roughness and cutting force obtained, respectively.
Authors: Toshiyuki Obikawa, Kazuhiro Funai
Abstract: Nickel alloy is widely applied to aero-engines, marine structures, chemical plants, etc. This alloy has superior mechanical and chemical properties, but is one of difficult-to-machine materials because of its superior properties. For this reason, various machining methods, such as cryogenic machining, hot machining, machining using high pressure coolant and rotary machining have been studied for increasing the cutting speed and cutting efficiency of this alloy. Recently, a new lubrication method called air jet assisted (AJA) machining was developed to extend tool life by 20-30% in finish-turning of Inconel 718 and Ti-6Al-4V. In this machining method air jet as well as coolant was applied to the cutting area. In this study, AJA machining was applied to high speed machining of Inconel 718 with a SiC whisker reinforced ceramic tool. The air jet was applied from an air nozzle at the tool flank face. Because the ceramic tool is likely to suffer from severe notch wear, the influence of AJA machining on flank and notch wear of the ceramic tool was investigated experimentally. As a result, it was found that as compared to conventional wet machining, AJA machining increased flank wear but reduced notch wear, which is usually critical to the tool life of the reinforced ceramic tool. The tool wear characteristics peculiar to AJA machining were effective for extending tool life in high speed machining of this alloy.
Authors: Piyapong Kumkoon, Chana Raksiri, Chaiyakorn Jansuwan
Abstract: This article aims to show the effects of the Micro-EDM process that influences the hole taper by comparing the parameters values during micro-drilling hole on the inconel 718 material. The condition of Micro-EDM drilling spark on the surface workpiece was 300 μm of depth and 200 μm of diameter tungsten carbide electrode. The experiment was carried out under the cover of hydrocarbon, using fluid dielectric cooling. The experiment parameters included on-time duty factor, off-time, voltage, frequency, and current, respectively. The experiment, it was found that the hole taper an immense effect on the machinability of drilling the workpieces, cause melting and recasting in the spark area, making a decrease in the ability of debris removal. Moreover, the experiment result, the tapered workpiece showed a minimized is 16.87 s, when using parameters at current 32 mA, frequency 150 Hz, and voltage 110 v, respectively. The optimal parameters to affected minimum hole taper is 0.195 degree, when using parameters at current 32 mA, frequency 130 Hz, and voltage 110 v, respectively.
Authors: A.K.M. Nurul Amin, Suhaily Mokhtar, Muammer Din Arif
Abstract: Inconel 718 is used for high-temperature applications in aerospace, nuclear, and automotive industries due to its resistance, at high temperatures, to corrosion, fatigue, creep, oxidation, and deformation. Unfortunately, these same qualities also impair its machinability and researchers have investigated on ways to machine it economically. Some unconventional machining practices such as: Plasma Enhanced and Laser Assisted Machining etc. have been applied. However these practices increase the machining cost. This research investigated the viability of high speed end milling of Inconel 718 using circular Silicon Nitride (ceramic) inserts under room temperature conditions. Tool wear (flank and notch wear), machining vibration amplitude and average surface roughness were evaluated for the feasibility analysis. A vertical CNC mill was used to machine Inconel 718 samples using different combinations of three primary machining parameters: cutting speed, feed, and depth of cut. Vibration data acquisition device and Datalog DasyLab 5.6 software were used to analyze machining vibration. Scanning Electron Microscope (SEM) and surface profilometer were utilized to measure tool (flank and notch) wear and surface roughness, respectively. It was observed that the machining vibrations, in high speed machining, was reasonable (0.045 V on the average). This resulted in acceptable tool wear (averages: flank wear = 0.25 mm, notch wear = 0.45 mm) and semi-finished surface roughness (0.30 µm) measured after every 30 mm length of cut. Thus, room temperature high speed machining of Inconel 718 using circular silicon nitride inserts is a practical option.
Authors: Zhe Chen, Ru Lin Peng, Pajazit Avdovic, Johan Moverare, Fredrik Karlsson, Jin Ming Zhou, Sten Johansson
Abstract: Inconel 718 is a nickel based superalloy that is widely used as a turbine disc material in gas turbine industries. This study details the effect of thermal exposure on the residual stresses produced when broaching Inconel 718. The chosen parameters for broaching in this study are similar to those used when manufacturing turbine discs. The broaching operation produced a high level of tensile residual stresses at the broached surface. A layer with tensile residual stresses was formed in the sub-surface region, followed by a layer several times thicker with compressive residual stresses. Thermal exposure was conducted at 550 °C. The depth distributions of residual stresses after thermal exposure are presented and discussed in this paper. Complete relaxation of the surface tensile residual stresses was observed after 30 h thermal exposure, whereas the 3000 h thermal exposure influenced both the surface and sub-surface residual stress states.
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