Effect of heat treatment on microstructure and mechanical properties of the hot-isostatic-pressed Inconel 718 powder compact

Chang, Litao; Sun, Wen‐Hua; Cui, Yue; Zhang, Faqiang; Yang, Rui

doi:10.1016/j.jallcom.2013.12.107

Cited by 76 publications

(32 citation statements)

References 21 publications

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“…The direct ageing heat treatment ensures a good balance of the strength and ductility. However, owing to over ageing of the precipitates, its yield strength is lower than that of the solution treated conditions [7].…”

Section: Introductionmentioning

confidence: 92%

“…It has been suggested that the standard AMS 5662 heat treatment recommended for wrought IN 718 is not appropriate for the direct HIP processed ones. This heat treatment results in the precipitation of carbide and 5 phase as well as the formation of thermal induced pores which lead to the decrease of grain boundary strength [6,7]. The direct ageing heat treatment ensures a good balance of the strength and ductility.…”

Section: Introductionmentioning

confidence: 99%

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Microstructural Analysis on 3D Printed Nickel-based Alloy 718

Aung¹,

Morton²,

Chen³

et al. 2014

8th International Symposium on Superalloy 718 and Derivatives (2014)

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Abstract3D printing is a rapidly growing technology for the fabrication of nickel-based alloy products in the aerospace industry because of its time efficiency, relative affordability, ease of use and design freedom. The alloy was initially built by selective laser melting technique, followed by stress relieving, hot isostatic pressing, and heat treatment processes. How process parameters affect the microstructure of 3D printed alloy 718, however, is not well understood. In this research, the grain size changes and the microstructural evolution of as-built samples were studied under different heat treatment conditions. The HT-1 treatment (solution treatment at 950 °C/1 h/water quenching followed by two-stage ageing at 720 °C/8 h/furnace cooling to 620 °C/8 h/air cooling to room temperature) reduced the grain size of aged microstructure twice compared with the standard AMS 5662 (solution treatment at 980 °C/1 h/water quenching followed by two-stage ageing at 720 °C/8 h/furnace cooling to 620 °C/8 h/air cooling to room temperature) due to the existence of acicular grain boundary 5 phase. However, the high volume fraction of y'/y" precipitates in the HT-2 (solution treatment at 1035 °C/1 h/water quenching followed by twostage ageing at 720 °C/10 h/furnace cooling to 620 °C/10 h/air cooling to room temperature) aged microstructure led to increase the microhardness value.

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Microstructural Analysis on 3D Printed Nickel-based Alloy 718

Aung¹,

Morton²,

Chen³

et al. 2014

8th International Symposium on Superalloy 718 and Derivatives (2014)

View full text Add to dashboard Cite

show abstract

“…Over aging of the precipitates in the direct aged alloy is the main reason for its relatively low yield strength; detailed analysis can be found in [16]. Low ductility of the solution and aged alloy is due to the decrease in inter-particle bonding, which is a result of precipitation of 5 phase and fine carbides during solution treatment.…”

Section: Response To Heat Treatmentmentioning

confidence: 99%

“…In the second part, the response of the alloy HIPed at an optimized temperature to typical heat treatments will be presented. Some of the results presented in these two parts have already been published [15,16]. The third part reports a new HIPing process that can eliminate the PPBs in HIPed PM Inconel 718 [17].…”

Section: Introductionmentioning

confidence: 99%

Development of Prior Particle Boundary Free Hot-Isostatic-Pressing Process for Inconel 718 Powder

Chang¹,

Yang²,

Sun³

et al. 2014

8th International Symposium on Superalloy 718 and Derivatives (2014)

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Hot isostatic pressed (HIPed) powder metallurgy (PM) Inconel 718 has the potential to be applied in turbine engines. However, the precipitation of high-density carbide particles along the prior particle boundaries (PPBs) leads to its poor ductility and is the main obstacle to be overcome if further and wider applications are pursued. In the past few years, we conducted research aimed at solving this problem, and a HIPing method that could eliminate the PPBs was developed. This paper summarizes the results in three parts: the first is on the influence of HIPing temperature on microstructure and tensile fracture modes of the HIPed alloy; several temperatures ranging from below the Laves incipient temperature to super-solidus were selected. In the second part, typical heat treatments for Inconel 718 were employed for mechanical property optimization of the HIPed alloy. It is found that HIPing at super-solidus temperatures could completely eliminate the PPBs, but the grain size is large and detrimental Laves phase also present. In the third part, a new HIPing process was developed, which consists of a short time holding above the solidus and a long time annealing below the incipient temperature of the Laves phase. This process could produce alloy free of PPBs and Laves phase. After heat treatment, the mechanical properties of the alloy are excellent.

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“…Mainly studies regarding hipping of nickel alloys powder are concentrated on studying the mechanical properties and microstructure of hipped parts [8,9]. Recently, Chang et al [8] studied the effect of hipping temperature on the microstructure and tensile properties of Inconel 718 powder compact.…”

Section: Introductionmentioning

confidence: 99%