Consolidation of Nickel Base Superalloys Powder by Low Pressure Plasma Deposition

1983 ◽  
Vol 30 ◽  
Author(s):  
R.W. Smith ◽  
L.G. Peterson ◽  
W.F. Schilling
Keyword(s):  
High Performance ◽  
Plasma Deposition ◽  
Titanium Aluminum ◽  
Turbine Disks ◽  
The Subject ◽  
Commercial Applications ◽  
Nickel Base ◽  
Rapidly Solidified ◽  
Solidification Technology ◽  
Rapid Solidification Technology

Powder Metallurgy (P/M) technology has seen an important series of advances in the past twenty-five or so years. It has progressed from a press + sinter methodology (which still has important uses) to one of being a complete processing technology where, ultimately, the structure and properties of totally new materials can be synthesized. A key step in this evolution was the application of P/M techniques to high performance materials such as nickel-based superalloys. This effort began in the early 1960's and has resulted in several important commercial applications such as P/M gas turbine disks and shafts.Attention has now turned to the potential use of Rapid Solidification Technology (RST) as a means of furthering the span of materials which can be made available for a wide variety of engineering applications. Rapidly solidified nickel, cobalt, titanium, aluminum and copper based materials are all the subject of extensive research and development at the present time (1).

Formation of bulk β–FeSi2by annealing rapidly solidified α–FeSi2ribbons

2000 ◽  
Vol 15 (5) ◽  
pp. 1045-1047 ◽  
Author(s):  
Zhenhua Zhou ◽  
Jianhua Zhao ◽  
Wenkui Wang ◽  
Liling Sun
Keyword(s):  
Rapid Solidification ◽  
Phase Evolution ◽  
Subsequent Annealing ◽  
Electric Resistance ◽  
Simple Method ◽  
Higher Temperature ◽  
Rapidly Solidified ◽  
Solidification Technology ◽  
Rapid Solidification Technology

Solidification of FeSi2alloy by single-roller rapid solidification technology was studied, and monophase α–FeSi2ribbons were obtained. Phase evolution of the monophase and metastable α–FeSi2ribbons during subsequent annealing was studied within situelectric resistance measurements. The results show that the metastable α–FeSi2phase transforms into the β–FeSi2phase at about 620 °C and then transforms into the α–FeSi2phase again at a higher temperature when heated. A new relatively simple method to prepare bulk β–FeSi2alloy, that is, formation of bulk β–FeSi2alloy by annealing monophase α–FeSi2alloy, is presented.

Comparison of Rapidly Solidified Nickel Base Superalloys Prepared by Melt Spinning and Plasma Deposition

1983 ◽  
Vol 28 ◽  
Author(s):  
A.I. Taub ◽  
M.R. Jackson ◽  
S.C. Huang ◽  
E.L. Hall
Keyword(s):  
Tensile Testing ◽  
Melt Spinning ◽  
Plasma Deposition ◽  
Nickel Base Superalloy ◽  
Petch Relation ◽  
Melt Spun ◽  
Nickel Base Superalloys ◽  
Nickel Base ◽  
Rapidly Solidified ◽  
Base Superalloy

ABSTRACTThe microstructure and yield strength of two nickel base superalloys prepared by melt spinning and plasma deposition are compared in the as-solidified condition and after annealing. The results support the interpretation of the yield strengths obtained by tensile testing melt spun ribbon as representative of the values obtained for bulk specimens with equivalent microstructures. The effectiveness of grain size strengthening in a nickel base superalloy is also examined. The Hall-Petch relation appears to be obeyed, with a slope k = .77±.15 MPa−m1/2.

The Influence of Si Content on the Microstructure of Rapidly Solidified AlMnSi Foil

2011 ◽  
Vol 295-297 ◽  
pp. 307-310
Author(s):  
Yan Li ◽  
Chuan Xin Zhai ◽  
Chun Hua Xu
Keyword(s):  
Phase Transformation ◽  
Heat Stability ◽  
Phase Transformation Temperature ◽  
Transmission Electron ◽  
Microstructure Morphology ◽  
Si Content ◽  
Rapidly Solidified ◽  
Si Addition ◽  
Solidification Technology ◽  
Rapid Solidification Technology

The AlMn and AlMnSi foils were fabricated by rapid solidification technology. The microstructures of the foils with various Si content were studied by transmission electron microscope (TEM). The phases of the foils were indentified by X-ray diffractometer (XRD); the phase transformation temperatures of the foils measured by differential scanning calorimeter (DSC). The results showed that addition of Si in the AlMn foil can improve the heat stability (phase transformation temperature) from 543K to over 873K. The addition of Si can change the phase structure of the foils. The phases of AlMn foil conclude Al and Al6Mn while the phases of AlMnSi foils with 3% Si or 5% Si addition become Al and Al4.01MnSi0.74. The addition of Si can also change the microstructure morphology of the foils from the rod, block and petal-like to the homogeneous globular. With the increase in Si content, the grain sizes of the foils were refined.

Spray Forming and Thermal Processing for High Performance Superalloys

2005 ◽  
Vol 475-479 ◽  
pp. 2773-2778 ◽  
Author(s):  
Guo Qing Zhang ◽  
Zhou Li ◽  
Zhong Wu Liu ◽  
Zhi Hui Zhang ◽  
Yifei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Processing ◽  
High Performance ◽  
Deposition Process ◽  
Spray Forming ◽  
Hot Workability ◽  
Forming Technology ◽  
Turbine Disks ◽  
New Processing ◽  
Rapidly Solidified

A unique pilot low-pressure spray forming plant was established and its spray atomisation and deposition process developed to study the new processing methods for high performance materials and to develop spray forming technology suitable for making sound superalloy preforms. The results indicated that high density (>99%) preforms (billets and rings) with little gas pick-ups and with the microstructural features of rapidly solidified superalloys, i.e. refined equiaxed grains and uniform microstructure, could be achieved after the optimisation of the spray atomisation and deposition process. The effects of subsequent thermal processing on the density, microstructure and mechanical properties of the spray formed superalloy were investigated. Compared to the turbine disks and rings made by wrought superalloys, the spray formed superalloys with identical chemistry showed significantly improved metallurgical quality, higher mechanical properties, and better hot workability.

Mechanical Properties of Rapidly Solidified Nickel-Base Superalloys and Intermetallics

1985 ◽  
Vol 58 ◽  
Author(s):  
A. I. Taub ◽  
M. R. Jackson
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Rapid Solidification ◽  
Plasma Deposition ◽  
Spray Forming ◽  
Hot Workability ◽  
Solidification Processing ◽  
Nickel Base ◽  
Rapidly Solidified

ABSTRACTThe improvements in the mechanical properties of nickel-base alloys that have been made possible by rapid solidification processing are reviewed. The results of processing by powder metallurgy, laser melting, low pressure plasma deposition and spray forming are examined. In general, the increased homogeneity obtained by rapid solidification allows for increased alloying and improved hot workability. The refined grain size improves the low and intermediate temperature strength, but leads to lower strengths at high temperature. For the high temperature applications, post solidification grain growth is required, as for example the directional recrystallization of powder metallurgy preforms. The development of a novel means of producing a fine dispersion from amorphous alloy precursors and the recent work attempting to improve the ductility of the intermetallic phases NiAl and Ni3A1 are also described.

scholarly journals Microstructural Characterization and Mechanical Properties of Rapidly Solidified Al-Si Systems by Chill Block Melt-Spinning Technique.

2020 ◽  
Vol 17 ◽  
pp. 79-91
Author(s):  
Amal Elsherif ◽  
Mustafa Kamal ◽  
Rizk Mostafa Shalaby
Keyword(s):  
Melt Spinning ◽  
Applied Load ◽  
Microstructural Characterization ◽  
Fine Grained ◽  
Chill Block ◽  
Rapidly Solidified ◽  
Hardness Values ◽  
Microstructural Examination ◽  
Solidification Technology ◽  
Rapid Solidification Technology

AlـSi alloys with compositions (0, 0.1, 0.5, 0.9 and 1.3 wt.% Si) were manufactured by chill block melt spinning method. The resulting ribbons samples have been characterized by xـray diffraction (XRD) and scanning electron microscope (SEM). Detailed analysis of (XRD) shows that presence of f.c.c Al solid solution and Si particles embedded within the aluminum grains. Microstructural examination resulted that microstructure of the melt spun ribbons are more fine and uniformly distributed. Rapid solidification technology led to increase the solubility of Si in αـAl as confirmed by XRD. Micro hardness measurements were also carried out by Vickers microـhardness tester at applied load 25gm forced and different dwell time. It is concluded that the Vickers hardness values are sensitive to applied load and indentation time. It is also found that the highest values of Hv is sensitive to presence of Si as columnar shape with fine grained of Al by high cooling rate.

Suppression of γ’ Precipitation in a Laser-Melted Nickel-Base Alloy

1977 ◽  
Vol 35 ◽  
pp. 270-271
Author(s):  
J. M. Walsh ◽  
J. C. Whittles ◽  
B. H. Kear ◽  
E. M. Breinan
Keyword(s):  
Cooling Rate ◽  
Base Alloy ◽  
Material Surface ◽  
Intimate Contact ◽  
Absorbed Power ◽  
Perfect Contact ◽  
Nickel Base ◽  
Rapidly Solidified ◽  
Limiting Case ◽  
The Heat Transfer Coefficient

Conventionally cast γ’ precipitation hardened nickel-base superalloys possess well-defined dendritic structures and normally exhibit pronounced segregation. Splat quenched, or rapidly solidified alloys, on the other hand, show little or no evidence for phase decomposition and markedly reduced segregation. In what follows, it is shown that comparable results have been obtained in superalloys processed by the LASERGLAZE™ method.In laser glazing, a sharply focused laser beam is traversed across the material surface at a rate that induces surface localized melting, while avoiding significant surface vaporization. Under these conditions, computations of the average cooling rate can be made with confidence, since intimate contact between the melt and the self-substrate ensures that the heat transfer coefficient is reproducibly constant (h=∞ for perfect contact) in contrast to the variable h characteristic of splat quenching. Results of such computations for pure nickel are presented in Fig. 1, which shows that there is a maximum cooling rate for a given absorbed power density, corresponding to the limiting case in which melt depth approaches zero.

The Nature of Delta Phase Precipitation in Inconel 718

1982 ◽  
Vol 40 ◽  
pp. 724-725
Author(s):  
L. S. Lin ◽  
C. C. Law
Keyword(s):  
Inconel 718 ◽  
Base Alloy ◽  
High Strength ◽  
Physical Metallurgy ◽  
Nickel Base Alloy ◽  
Phase Precipitation ◽  
Weight Percentage ◽  
Delta Phase ◽  
The Subject ◽  
Nickel Base

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).

Performance Management Transformation

2020 ◽  
Keyword(s):  
Organizational Performance ◽  
Performance Management ◽  
High Performance ◽  
Best Practice ◽  
Call To Action ◽  
Daily Work ◽  
The Past ◽  
Great Debate ◽  
The Subject ◽  
New Research

No other talent process has been the subject of such great debate and emotion as performance management (PM). For decades, different strategies have been tried to improve PM processes, yielding an endless cycle of reform to capture the next “flavor-of-the-day” PM trend. The past 5 years, however, have brought novel thinking that is different from past trends. Companies are reducing their formal processes, driving performance-based cultures, and embedding effective PM behavior into daily work rather than relying on annual reviews to drive these. Through case studies provided from leading organizations, this book illustrates the range of PM processes that companies are using today. These show a shift away from adopting someone else’s best practice; instead, companies are designing bespoke PM processes that fit their specific strategy, climate, and needs. Leading PM thought leaders offer their views about the state of PM today, what we have learned and where we need to focus future efforts, including provocative new research that shows what matters most in driving high performance. This book is a call to action for talent management professionals to go beyond traditional best practice and provide thought leadership in designing PM processes and systems that will enhance both individual and organizational performance.

Review on modification strategies of polyethylene/polypropylene immiscible thermoplastic polymer blends for enhancing their mechanical behavior

2018 ◽  
Vol 51 (4) ◽  
pp. 291-336 ◽  
Author(s):  
Antimo Graziano ◽  
Shaffiq Jaffer ◽  
Mohini Sain
Keyword(s):  
High Performance ◽  
Cost Effective ◽  
Good Method ◽  
Waste Recycling ◽  
Industrial Applications ◽  
Polymer Waste ◽  
Reactive Compatibilization ◽  
Brittle To Ductile Transition ◽  
Commercial Applications ◽  
Effective Product

Blends of polyethylene (PE) and polypropylene (PP) have always been the subject of intense reasearch for encouraging polymer waste recycling while producing new materials for specific applications in a sustainable way. However, being thermodynamically immiscible, these polyolefins form a binary system usually exhibiting lower performances compared with those of the homopolymers. Many studies have been carried out to better understand the PE/PP blend compatibilization for developing a high-performance and cost-effective product. Both nonreactive and reactive compatibilization promote the brittle to ductile transition for a PE/PP blend. However, the final product usually does not meet the requirements for high demanding commercial applications. Therefore, further PE/PP modification with a reinforcing filler, being either synthetic or natural, proved to be a good method for manufacturing high-performance reinforcend polymer blend composites, with superior and tailored properties. This review summarizes the recent progress in compatibilization techniques applied for enhancing the interfacial adhesion between PE and PP. Moreover, future perspectives on better understanding the influence of themodynamics on PE/PP synergy are discussed to introduce more effective compatibilization strategies, which will allow this blend to be used for innovative industrial applications.

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