A Microstructure Evolution Model for the Processing of Single-Crystal Alloy CMSX-4 Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair (Part II)

2014 ◽  
Vol 45 (6) ◽  
pp. 2279-2290 ◽  
Author(s):  
Ranadip Acharya ◽  
Rohan Bansal ◽  
Justin J. Gambone ◽  
Suman Das
Author(s):  
Warren Miglietti ◽  
Jeff Benson ◽  
Fritz Blum ◽  
Philip Harms ◽  
Ros Pennefather

Gas tungsten arc welding (GTAW) using AC or DC current types has been utilised for the manufacture and repair of turbine engine components for many years. The weld repair of single crystal components such as turbine blade tips is also important. However, welding of a single crystal alloy has its associated problems (which will be discussed later). SMP14 is an advanced single crystal, Ni-base superalloy used for turbine blading. This alloy has enhanced mechanical properties at elevated temperatures when compared to equiaxed, directionally solidified and first generation single crystal superalloys. The objective of this task is to investigate the weldability of SMP14 using the new variable polarity GTAW process. Metallurgical investigations were undertaken to evaluate the microstructure of the welded region. Microporosity was found in the weld and there was no evidence of recrystallization, sub-grains beneath the weld or microcracking/microfissuring. Tensile test evaluations revealed that a high strength weld equivalent to equiaxed MAR-M247, Ni-based superalloy could be achieved. This appears to be the highest weld mechanical strength achieved to date when joining any Ni-base single crystal alloy together. Fractography was also utilised to analyse the fracture surfaces of the tensile test samples. Oxidation tests also revealed that the oxidation resistance of the weld was good and will be suitable for weld tip restoration where the weld needs to have good oxidation resistance.


Alloy Digest ◽  
1992 ◽  
Vol 41 (11) ◽  

Abstract CMSX-2 is a single crystal alloy development of Cannon-Muskegon Corporation designed to achieve a high level of balanced properties. This datasheet provides information on composition, physical properties, as well ascreep and fatigue. Filing Code: Ni-417. Producer or source: Cannon-Muskegon Corporation.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jianing Wang ◽  
Jieshi Chen ◽  
Zhiyuan Zhang ◽  
Peilei Zhang ◽  
Zhishui Yu ◽  
...  

Purpose The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment. Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of interfacial layer was different due to the different mechanism of element diffusion of the two substrates. The PC Ni substrate mainly provided Ni atoms through grain boundary diffusion. The Ni3Sn4 phase of the Sn0.05Ni/PC Ni joint was finer, and the diffusion flux of Sn and Ni elements increased, so the Ni3Sn4 layer of this joint was the thickest. The SC Ni substrate mainly provided Ni atoms through the lattice diffusion. The Sn0.1Ni/SC Ni joint increases the number of Ni atoms at the interface due to the doping of 0.1Ni (wt.%) elements, so the joint had the thickest NiSn4 layer. Design/methodology/approach The effects of doping minor Ni on the microstructure evolution of an Sn-xNi (x = 0, 0.05 and 0.1 Wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment was investigated in this study. Findings Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of the interfacial layer was different due to the different mechanisms of element diffusion of the two substrates. Originality/value In this study, the effect of doping Ni on the growth and formation mechanism of IMCs of the Sn-xNi/Ni (single-crystal) solder joints (x = 0, 0.05 and 0.1 Wt.%) was investigated.


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