scholarly journals Turbine Blade Tip Repair by Laser Directed Energy Deposition Additive Manufacturing Using a Rene 142–MERL 72 Powder Blend

2021 ◽  
Vol 5 (1) ◽  
pp. 21
Author(s):  
Mohsen K. Keshavarz ◽  
Alexandre Gontcharov ◽  
Paul Lowden ◽  
Anthony Chan ◽  
Devesh Kulkarni ◽  
...  

Laser directed energy deposition (LDED) was used with a powder blend comprising 75 wt.% Rene 142 and 25 wt.% of Merl 72 (4275M72) for turbine blade tip repair applications. Sound samples could be deposited at ambient temperature on Haynes 230. The microstructural analyses showed the presence of fine gamma prime precipitates in the as-deposited samples, while after aging, the alloy possessed around 40 vol.% with a bimodal precipitate size distribution. Also, the alloy contained Ta-Hf-W carbides in different sizes and shapes. Tensile testing from room temperature up to 1366 K was performed. The 4275M72 deposits possessed higher tensile properties compared to Rene 80 in this temperature range but lower elongations at the elevated temperatures. The creep properties of 4275M72 samples at 1255 K were superior to Rene 80. Also, the oxidation resistance of deposited 4275M72 was similar to Rene 142. The combination of high mechanical properties, creep behavior, and oxidation resistance of LDEDed 4275M72 makes it a suitable alloy for tip repair of turbine blades.

2019 ◽  
Vol 304 ◽  
pp. 01023
Author(s):  
Adrien Doux ◽  
Vincent Philippe

Directed Energy Deposition (DED) Additive Manufacturing (AM) processes have a great potential to be used as cost-effective and efficient repairing and re-manufacturing processes for aerospace components such as turbine blades and landing gears. The AMOS project intends to connect repair and re-manufacturing strategies with design through accurate DED process simulation and novel multi-disciplinary design optimisation (MDO) methods. The ultimate goal is to reduce aerospace component weaknesses at design stage and prolong their lifecycles. DED AM processes are multi-physical phenomena involving high laser power melting powder or wire on a substrate. An experimental heat source has been calibrated using a heat transfer analysis of IN718 laser and powder AM on a sample part. Residual stresses and final distortion are also computed using thermal field and the evolving part distortion at each increment. Multiple hypotheses have been considered model the molten pool creation on the Heat Affected Zone (HAZ).


Author(s):  
Daniel Andres Rojas Perilla ◽  
Johan Grass Nuñez ◽  
German Alberto Barragan De Los Rios ◽  
Fabio Edson Mariani ◽  
Reginaldo Teixeira Coelho

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 634
Author(s):  
Agnieszka Kisielewicz ◽  
Karthikeyan Thalavai Pandian ◽  
Daniel Sthen ◽  
Petter Hagqvist ◽  
Maria Asuncion Valiente Bermejo ◽  
...  

This study investigates the influence of resistive pre-heating of the feedstock wire (here called hot-wire) on the stability of laser-directed energy deposition of Duplex stainless steel. Data acquired online during depositions as well as metallographic investigations revealed the process characteristic and its stability window. The online data, such as electrical signals in the pre-heating circuit and images captured from side-view of the process interaction zone gave insight on the metal transfer between the molten wire and the melt pool. The results show that the characteristics of the process, like laser-wire and wire-melt pool interaction, vary depending on the level of the wire pre-heating. In addition, application of two independent energy sources, laser beam and electrical power, allows fine-tuning of the heat input and increases penetration depth, with little influence on the height and width of the beads. This allows for better process stability as well as elimination of lack of fusion defects. Electrical signals measured in the hot-wire circuit indicate the process stability such that the resistive pre-heating can be used for in-process monitoring. The conclusion is that the resistive pre-heating gives additional means for controlling the stability and the heat input of the laser-directed energy deposition.


2021 ◽  
Vol 65 ◽  
pp. 407-417
Author(s):  
Geng Li ◽  
Kyle Odum ◽  
Curtis Yau ◽  
Masakazu Soshi ◽  
Kazuo Yamazaki

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