Influence of thermal shocks at high temperatures on microstructure and hardness of RENE 41 alloy

Science and Technology of Welding and Joining

Ganguly

Pardal

2023

Creep-resistant nickel, cobalt based superalloys, selected for a high-speed flight application, deposited using Wire + Arc Additive Manufacturing (WAAM), was reported. Three different alloys, Haynes 188, Inconel 718, and Rene 41, were deposited, and tested for their hightemperature tensile properties, and the results compared with wrought data. The alloys were tested from ambient temperature to 1000°C in their as-deposited condition and after undergoing industry standard age-hardening and solutionising heat-treatments, to down select the best performing alloy under two different processing conditions. The mechanical strength of the alloys fell short of the maximum achievable in wrought condition. Precipitation-strengthened alloys, Inconel 718 and Rene 41 were found to have underperformed the most significantly, whereas solid-solution-strengthened Haynes 188 suffered the least due to WAAM.

Section: Rene 41mentioning

confidence: 99%

A performance comparison of additive manufactured creep-resistant superalloys

Science and Technology of Welding and Joining

Ganguly

Pardal

2023

“…This is consistent with the nding of Ungureanu et al . In their study, RE41 underwent a thermal shock process to understand the effects on the microstructure, at 1000 °C it was found that with increased thermal shock oxide layers were seen to grow and retain a similar distribution of the alloying elements [27]. Ultimately, the formation of oxide in the samples is consistent with the tensile results, as the elongation of the samples represent only a fraction of the expected elongation from wrought material, indicating that the presents of oxide has affected the ductility of the alloy.…”

Section: Fractographymentioning

confidence: 99%

High Temperature Failure and Microstructural Investigation of Additive Manufactured Rene 41

Ganguly²,

Pardal³

2022

Preprint

In developing a wire-arc direct energy deposition process for creep resistant alloys used in high-speed flight applications, structures were built from nickel-based superalloy Rene 41. Samples of AM material were analysed for their microstructural and mechanical properties, in both as deposited (AD) and heat-treated (HT) conditions. Tensile specimens were tested at room-temperature, 538, 760, and 1000 °C. Macroscopically, large columnar grains made up of a typical dendritic structure were observed. Microscopically, significant segregation of heavier elements, grain boundary precipitates, and secondary phases were observed, with key differences observed in HT material. There was a clear distinction between failure modes at different testing temperatures and between AD and HT variants. A fractographic investigation found a progressive move from brittle to ductile fracture with increasing testing temperature in both AD and HT conditions, as well as microstructural features which support this observation.

High-temperature failure and microstructural investigation of wire-arc additive manufactured Rene 41

Int J Adv Manuf Technol

Ganguly

Pardal

2023

In developing a wire-arc plasma direct energy deposition process for creep-resistant alloys used in high-speed flight applications, structures were built from nickel-based superalloy Rene 41. Samples of additive manufacturing (AM) material were analysed for their microstructural and mechanical properties, in both as-deposited (AD) and heat-treated (HT) conditions. Tensile specimens were tested at room temperature, 538, 760, and 1000 °C. Macroscopically, large columnar grains made up of a typical dendritic structure were observed. Microscopically, significant segregation of heavier elements, grain boundary precipitates, and secondary phases were observed, with key differences observed in HT material. There was a clear distinction between failure modes at different testing temperatures and between AD and HT variants. A fractographic investigation found a progressive move from brittle to ductile fracture with increasing testing temperature in both AD and HT conditions, as well as microstructural features which support this observation.