Effect of Pre-weld Solution Treatment on Mechanical Properties and Microstructure of Micro-Plasma Arc Welded Inconel 718

2019 ◽  
pp. 373-383
Author(s):  
Ajit Kumar Sahu ◽  
Swarup Bag
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Solution Treatment ◽  
Plasma Arc

scholarly journals Effects of the γ″-Ni3Nb Phase on Mechanical Properties of Inconel 718 Superalloys with Different Heat Treatments

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 151
Author(s):  
Li-Shi-Bao Ling ◽  
Zheng Yin ◽  
Zhi Hu ◽  
Jin-Hui Liang ◽  
Zhi-Yong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Inconel 718 ◽  
Hot Isostatic Pressing ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Strengthening Mechanism ◽  
Morphological Observation ◽  
Isostatic Pressing ◽  
Direct Aging

The effects of the γ″-Ni3Nb phase on the mechanical properties of Inconel 718 superalloys, with standard heat treatment, hot isostatic pressing + solution treatment + aging, and hot isostatic pressing + direct aging, were characterized by morphological observation, X-ray diffraction, and tensile experiments. The results of the morphological observation revealed that many fine γ″ precipitates of ~26.49 ± 1.82 nm in mean size were formed in all samples. However, the relatively coarser γ″ precipitates formed in the grain boundaries were only observed in the sample treated with hot isostatic pressing + direct aging. The yield strengths of the hot isostatic pressing + direct aging sample at room temperature and at 650 °C both exhibited the maximum values about 993 ± 5.7 and 811 ± 12.6 MPa, respectively. The γ″ precipitate was considered to be the dominant strengthening phase in the sample according to the lattice misfits (ε) of γ/γ″. The strengthening mechanism of the samples can be explained as the coherency strain strengthening of fine γ″ precipitates. Moreover, due to the coarser γ″ precipitates in the grain boundaries, dislocation-cut ordered particle strengthening also occurred in the sample after hot isostatic pressing + direct aging treatment.

Effect of Solution Treatment on Microstructure and Mechanical Properties of Graphene Nanoplatelets Reinforced Inconel 718 Composites by Selective Laser Melting

2016 ◽  
Author(s):  
Yachao Wang ◽  
Jing Shi ◽  
Xiaoyang Deng ◽  
Shiqiang Lu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Inconel 718 ◽  
Solution Treatment ◽  
Graphene Nanoplatelets ◽  
Filler Material ◽  
Strengthening Effect ◽  
Laser Melting

Graphene nanoplatelets (GNPs) have many outstanding properties, such as high mechanical strengths, light weight, and high electric conductivity. These unique properties make it an ideal filler material for various composites. On the other hand, the development MMNCs (metal matrix nanocomposites) through additive manufacturing (AM) processes has become a major innovation in the field of advanced structural materials, owing to shorter production lead time, less material waste, high production flexibility. It is of great innovativeness to have the attractive features combined to produce GNPs reinforced MMNCs using AM techniques. In addition, metal components produced by laser assisted additive manufacturing (LAAM) methods usually have inferior mechanical properties, as compared to the counterparts by the traditional metal forming processes. To achieve optimized mechanical properties, the obtained MMNCs are subjected to various post treatment routines and the effect of post heat treatment on material properties is investigated. In this study, pure Inconel 718 and GNPs reinforced IN718 with 1.1 vol.% and 4.4 vol.% filler material are fabricated by selective laser melting (SLM). Room temperature tensile tests are conducted to evaluate the tensile properties. Scanning electron microscopy (SEM) observations are conducted to analyze the microstructure of materials and to understand the reinforcing mechanism. It is found that fabrication of GNPs reinforced MMC using SLM is a viable approach. The obtained composites possess dense microstructure and enhanced tensile strength. The strengthening effect and mechanisms involved in the composites are discussed. Solution treatments at three levels of temperature (940, 980, and 1020°C) for 1 hour period are carried out to evaluate the effect of the heat treatment on the material microstructure and therefore the resulted mechanical properties of the composite material. The results of samples with and without heat treatment are also compared. The experiments results indicate that that addition of GNPs into Inconel 718 results in significant strength improvement. Moreover, at any volume content of reinforcement, higher solution treatment leads to lower strength, mainly due to coarsened microstructure. The addition of GNPs effectively inhibits the grain growth during the post heat process and the average grain size is significantly refined compared to unreinforced samples. Moreover, through the investigation of various strengthening mechanisms, it is found that Orowan strengthening effect is small and can be neglected for both as-built and heat treated conditions. Load transfer effect is the dominating strengthening effect among all contributors and solution treatment significantly reduces thermal mismatch strengthening.

scholarly journals Enhancing Mechanical Properties of the Spark Plasma Sintered Inconel 718 Alloy by Controlling the Nano-Scale Precipitations

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3336
Author(s):  
Shuaijiang Yan ◽  
Yun Wang ◽  
Qingxiang Wang ◽  
Chengsong Zhang ◽  
Dazhi Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Inconel 718 ◽  
Production Efficiency ◽  
Solution Treatment ◽  
Inconel 718 Alloy ◽  
Direct Aging ◽  
Spark Plasma

The present study aimed to optimize the phase constituents and mechanical properties of the spark plasma sintered (SPS) Inconel 718 (IN718) alloy. A series of heat treatment routes were designed based on the phase relations in IN718 and performed for the optimization. The microstructure and phase compositions of the SPS IN718 alloys were examined by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), and transmission electron microscopy (TEM). The mechanical properties of the samples were characterized at room temperature and at 650 °C. The results showed that large amounts of γ” (Ni3Nb) and γ’ (Ni3(Al, Ti)) strengthening phases precipitated in the IN718 alloy after direct aging (DA) of the as-fabricated sample. Moreover, the mechanical properties of the DA sample were comparable to that of the best one of the solution-treated and aged counterparts. The analysis showed that the rapid sintering and solid solution treatment of the IN718 alloy were achieved simultaneously by SPS. In the case of the SPS IN718 material, the direct aging regime had the same heat treatment effect as the conventional solid solution and aging treatment. This contributes toward improving the production efficiency and reduces manufacturing costs in the actual production process.

scholarly journals Effect of homogenization and solution treatments time on the elevated-temperature mechanical behavior of Inconel 718 fabricated by laser powder bed fusion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eslam M. Fayed ◽  
Mohammad Saadati ◽  
Davood Shahriari ◽  
Vladimir Brailovski ◽  
Mohammad Jahazi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Elevated Temperature ◽  
Mechanical Behavior ◽  
Inconel 718 ◽  
Treatment Time ◽  
Solution Treatment ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

AbstractIn the present study, the effect of homogenization and solution treatment times on the elevated-temperature (650 °C) mechanical properties and the fracture mechanisms of Inconel 718 (IN718) superalloy fabricated by laser powder bed fusion (LPBF) was investigated. Homogenization times between 1 and 7 h at 1080 °C were used, while solution treatments at 980 °C were performed in the range from 15 to 60 min. The as-printed condition showed the lowest strength but the highest elongation to failure at 650 °C, compared to the heat-treated conditions. After heat treatments, the strength of the IN718 alloy increased by 20.3–31% in relation to the as-printed condition, depending on the treatment time, whereas the ductility decreased significantly, by 67.4–80%. Among the heat treatment conditions, the 1 h homogenized conditions at 1080 °C (HSA1 and HSA2) exhibited the highest strength and ductility due to the combined effects of the precipitation hardening and sub-structural changes. Further increases in the homogenization time to 4 and 7 h led to a decrease in the strength and significant ductility loss of the LPBF IN718 due to the considerable annihilation of the dislocation tangles and a greater precipitation of coarse MC carbide particles. Furthermore, it was found that the solution treatment duration had a crucial influence on the mechanical properties at 650 °C due to the increase in the grain boundary strength through the pinning effect of the intergranular δ-phase. In addition, the fracture mechanism of the LPBF IN718 was found to be dependent on the heat treatment time. Finally, this investigation provides a map that summarizes the effect of homogenization and solution treatment times on the high-temperature mechanical behavior of LPBF IN718 by relating it to the corresponding microstructural evolution. This effort strives to assist in tailoring the mechanical properties of LPBF IN718 based on the design requirements for some specific applications.

High temperature mechanical properties of Inconel 718 pulsed Nd–YAG laser welds

2006 ◽  
Vol 23 (1) ◽  
pp. 29-37 ◽  
Author(s):  
G.D. Janaki Ram ◽  
A. Venugopal Reddy ◽  
K. Prasad Rao ◽  
G. Madhusudhan Reddy
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Inconel 718 ◽  
Yag Laser ◽  
High Temperature Mechanical Properties ◽  
Laser Welds

Influence of Keyhole Mode of Plasma Arc Welding on Microstructure and Mechanical Properties of Similar Butt-Welded Incoloy 800H

2019 ◽  
Vol 45 (2) ◽  
pp. 1135-1142
Author(s):  
T. M. Harish ◽  
S. Jerome ◽  
B. Yadukrishna ◽  
Rishi S. Kumar ◽  
C. Midhun Suresh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Incoloy 800H ◽  
Microstructure And Mechanical Properties

Powder plasma arc additive manufactured CoCrFeNi(SiC)x high-entropy alloys: Microstructure and mechanical properties

2021 ◽  
Vol 282 ◽  
pp. 128736 ◽  
Author(s):  
Qingkai Shen ◽  
Xiangdong Kong ◽  
Xizhang Chen ◽  
Xukai Yao ◽  
Vladislav B. Deev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Entropy Alloys ◽  
Plasma Arc ◽  
High Entropy ◽  
Microstructure And Mechanical Properties

Mechanical Properties and Aging Behavior of Ultrafine Grained Al-Ag Alloy Fabricated by Accumulative Roll-Bonding

2014 ◽  
Vol 794-796 ◽  
pp. 851-856
Author(s):  
Tadashiege Nagae ◽  
Nobuhiro Tsuji ◽  
Daisuke Terada
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Accumulative Roll Bonding ◽  
Precipitation Hardening ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
High Strength ◽  
Subsequent Aging ◽  
Roll Bonding ◽  
Ultrafine Grained

Accumulative roll-bonding (ARB) process is one of the severe plastic deformation processes for fabricating ultrafine grained materials that exhibit high strength. In aluminum alloys, aging heat treatment has been an important process for hardening materials. In order to achieve good mechanical properties through the combination of grain refinement hardening and precipitation hardening, an Al-4.2wt%Ag binary alloy was used in the present study. After a solution treatment at 550°C for 1.5hr, the alloy was severely deformed by the ARB process at room temperature (RT) up to 6 cycles (equivalent strain of 4.8). The specimens ARB-processed by various cycles (various strains) were subsequently aged at 100, 150, 200, 250°C, and RT. The hardness of the solution treated (ST) specimen increased by aging. On the other hand, hardness of the ARB processed specimen decreased after aging at high temperatures such as 250°C. This was probably due to coarsening of precipitates or/and matrix grains. The specimen aged at lower temperature showed higher hardness. The maximum harnesses achieved by aging for the ST specimen, the specimens ARB processed by 2 cycles, 4 cycles and 6 cycles were 55HV, 71HV, 69HV and 65HV, respectively. By tensile tests it was shown that the strength increased by the ARB process though the elongation decreased significantly. However, it was found that the tensile elongation of the ARB processed specimens was improved by aging without sacrificing the strength. The results suggest that the Al-Ag alloy having large elongation as well as high strength can be realized by the combination of the ARB process for grain refinement and the subsequent aging for precipitation hardening.

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