Dissimilar vacuum brazing of WC-Co and cold work steel utilizing a new near-eutectic silver-copper filler alloy

2019 ◽  
Vol 234 (6-7) ◽  
pp. 1019-1031
Author(s):  
Ahmed AD Sarhan
Keyword(s):  
Tungsten Carbide ◽  
Cold Work ◽  
Research Work ◽  
High Strength ◽  
Filler Alloy ◽  
Tungsten Carbides ◽  
Silver Copper ◽  
Final Assembly ◽  
Brazed Joint ◽  
Tool Shank

Tungsten carbides are extremely high in hardness and they are wear-resistant materials. However, they are extremely brittle materials that render them ideal for many applications. Brazing technology has been proved to be a promising approach for joining tungsten carbide to tough metals to create high strength, tough and impact-resistant joint in the final assembly. In this research work, a dissimilar brazing of tungsten carbide (WC-Co) and cold work steel will be achieved using a new type of filler, a silver-copper near-eutectic alloy (BAg-8T) (Ag70Cu28Ti2). (BAg-8T) as a mixed alloy (eutectic and titanium) can melt/solidify completely in a very narrow temperature range (778 °C/800 °C), lower than any other existing brazing filler alloy; this will reduce the possibility of partial fastening while solidification. In addition, (BAg-8T) filler will act as the soft-iron gauze. Being soft and ductile metals, they will creep and absorb the movement due to differential contraction of the carbide and tool shank. Besides, they will improve the wetting on the carbide. In this research work, the effect of the joining parameters (brazing temperature and cobalt percentage in the tungsten carbide) on the mechanical properties and microstructure of the brazed joint will be investigated to determine the best joint performance.

Interfacial Behaviors of Vacuum Brazed Joint between Diamond Grit and Ni-13Sn-28Cr Filler Alloy

2013 ◽  
Vol 705 ◽  
pp. 132-142
Author(s):  
Jong Oh Ham ◽  
Jin Hwan Chung ◽  
Sang Kyo Jung ◽  
Young Min Byoun ◽  
Chi Hwan Lee
Keyword(s):  
Thermal Stability ◽  
Shear Strength ◽  
Chromium Carbide ◽  
High Strength ◽  
Filler Alloy ◽  
Stability Evaluation ◽  
Diamond Grit ◽  
Vacuum Brazing ◽  
Best Value ◽  
Brazed Joint

In this study, vacuum brazing of diamond grit was performed using an Ni-10Sn-28Cr alloy in order to examine the interfacial behaviors. In order to study the wettability between diamond grit and the brazing alloy, a graphite was used instead of diamond grit. The contact angle of Ni-10Sn-28Cr alloy and graphite decreased with increasing holding time and temperature. The shear strength between graphite and Ni-10Sn-28Cr filler alloy showed the best value of 29.8 MPa at 1100°C brazing temperature. It was shown that the shear strength was decreased significantly due to the increase of the thickness of brittle reaction layer and interface residual stress, as the brazing temperature increased up to 1200°C. In regards to the thermal stability evaluation of diamond grits, the graphitization of diamond grit was observed to occur at 1300°C brazing temperature after 60 minutes. Beyond 1100°C brazing temperature, diamond grit exhibited ideal setting in the brazing filler alloy, whereas process diamond grit was observed to be fully embedded in the brazing alloy and damaged at 1200°C temperature. The results of interface analysis of the diamond grit joints brazed by the brazing alloy showed that the chromium carbides played an important role in high strength bonding and as the brazing temperature increased, existing angular chromium carbide transformed into acicular chromium carbide.

TELNIC BRONZE

Alloy Digest ◽  
1953 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Base Alloy ◽  
Cold Work ◽  
High Strength ◽  
Heat Treating ◽  
Hot Workability ◽  
Copper Base ◽  
Copper Base Alloy

Abstract Chase TELNIC BRONZE is a high strength copper-base alloy, hardenable both by heat treatment and cold work, and also having good conductivity, corrosion resistance, cold and hot workability, and excellent machinability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: Cu-4. Producer or source: Chase Brass & Copper Company Inc..

Third Order Elastic Constants and Rayleigh Wave Dispersion of Shot Peened Aero-Engine Materials

2013 ◽  
Vol 768-769 ◽  
pp. 201-208 ◽  
Author(s):  
Marek Rjelka ◽  
Martin Barth ◽  
Sven Reinert ◽  
Bernd Koehler ◽  
Joachim Bamberg ◽  
...  
Keyword(s):  
Residual Stress ◽  
Rayleigh Wave ◽  
Elastic Constants ◽  
Cold Work ◽  
High Strength ◽  
Wave Dispersion ◽  
Third Order ◽  
Third Order Elastic Constants ◽  
Aero Engine ◽  
Rayleigh Wave Dispersion

Aero-engine components exposed to high mechanical stresses are made of high-strength alloys and additionally, they are surface treated by shot peening. This process introduces compressive residual stress into the material making it less sensitive to stress corrosion cracking and fatigue and therefore benefits the components performance and lifetime. Moreover cold work is induced in an amount depending on the peening parameters. To approximate the remaining lifetime, a quantitative, non-destructive method for stress assessment is required. It was shown that surface treatment of such alloys can be characterized by broadband Rayleigh wave dispersion measurements. However, the relative contributions of residual stress and cold work, respectively, remained an open point. This paper presents the determination of third order elastic constants (TOEC) for IN718 and Ti6246, providing, together with a model for the inversion of dispersion data, a quantitative access to the acoustoelastic effect. Finally, some measurements of differently treated samples are given.

scholarly journals Optimization of Drilling Process Parameters Via Taguchi, TOPSIS and RSA Techniques

2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Research Work ◽  
Cutting Speed ◽  
High Strength ◽  
Drilling Process ◽  
Drill Bit ◽  
Influence Of Process Parameters ◽  
Light Trucks ◽  
Cfrp Composite

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.

Effect of boron on the continuous cooling transformation kinetics in a low carbon advanced ultra-high strength steel (A-UHSS)

2012 ◽  
Vol 1485 ◽  
pp. 83-88 ◽  
Author(s):  
G. Altamirano ◽  
I. Mejía ◽  
A. Hernández-Expósito ◽  
J. M. Cabrera
Keyword(s):  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Characterization ◽  
Low Carbon ◽  
Transformation Kinetics ◽  
Cooling Rates ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Cct Diagrams

ABSTRACTThe aim of the present research work is to investigate the influence of B addition on the phase transformation kinetics under continuous cooling conditions. In order to perform this study, the behavior of two low carbon advanced ultra-high strength steels (A-UHSS) is analyzed during dilatometry tests over the cooling rate range of 0.1-200°C/s. The start and finish points of the austenite transformation are identified from the dilatation curves and then the continuous cooling transformation (CCT) diagrams are constructed. These diagrams are verified by microstructural characterization and Vickers micro-hardness. In general, results revealed that for slower cooling rates (0.1-0.5 °C/s) the present phases are mainly ferritic-pearlitic (F+P) structures. By contrast, a mixture of bainitic-martensitic structures predominates at higher cooling rates (50-200°C/s). On the other hand, CCT diagrams show that B addition delays the decomposition kinetics of austenite to ferrite, thereby promoting the formation of bainitic-martensitic structures. In the case of B microalloyed steel, the CCT curve is displaced to the right, increasing the hardenability. These results are associated with the ability of B atoms to segregate towards austenitic grain boundaries, which reduce the preferential sites for nucleation and development of F+P structures.

DEUTSCHE EDELSTAHLWERKE CRYODUR 2242

Alloy Digest ◽  
2021 ◽  
Vol 70 (8) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Cold Work ◽  
High Strength ◽  
Heat Treating ◽  
Vanadium Alloy ◽  
Medium Carbon ◽  
High Toughness ◽  
Specialty Steel ◽  
Cold Work Tool Steel

Abstract Deutsche Edelstahlwerke Cryodur 2242 is a medium-carbon, chromium-vanadium alloy cold-work tool steel that has medium hardenability and is suitable for applications requiring a combination of high strength, high toughness, and good wear resistance. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-816. Producer or source: Deutsche Edelstahlwerke Specialty Steel.

New high-strength, corrosion-resistant alloys for marine corrosion, fastener and boat shaft applications

2012 ◽  
Author(s):  
Edward Hibner ◽  
Pete Jones
Keyword(s):  
Corrosion Resistance ◽  
Hydrogen Embrittlement ◽  
Yield Strength ◽  
Cold Work ◽  
High Strength ◽  
Age Hardening ◽  
Marine Corrosion ◽  
Corrosion Resistant ◽  
Excellent Corrosion Resistance ◽  
Cold Worked

High strength and corrosion resistant nickel alloys Hastelloy C-86 ® (UNS N06686) and Hastelloy C-22HS ® (UNS N07022) are currently being evaluated and/ or used by the Navy for current and future bolting applications where both high strength, toughness, ductility along with excellent resistance to corrosion and hydrogen embrittlement are required. This includes present and new ship design. The 686 alloy is currently into final stages of data gathering and mil spec preparation. Alloy 686 is a solid solution nickel base alloy obtaining it’s strength through cold work. The C-22HS alloy was recently introduced for applications requiring both corrosion resistance and high strength. Being a C-type alloy (Ni-Cr-Mo), C- 22HS has excellent corrosion resistance in both reducing and oxidizing environments. The alloy is capable of being age-hardened to effectively double the yield strength over other Ctype alloys. The C-22HS alloy has generated interest in the oil & gas industry due to its resistance to sour brine environments. C-22HS is being included in NACE MR0175/ISO 15156 at NACE Level VII (highest severity), exhibiting resistance to severe sour brine environments. Properties of the new alloy relevant to marine corrosion and Navy fastener applications are presented. This material has also been shown to be resistant to hydrogen embrittlement in marine and other severe environments, exhibiting potential for corrosion immunity. Efforts in developing alternate processing routes for C-22HS alloy for very high strength applications are detailed. The high strength of C-22HS alloy is imparted through the formation of Long Range Ordering (LRO) domains of Ni2(Cr, Mo) which develop during a two-step age-hardening treatment. In standard C-22HS alloy, the formation of the LRO domains nearly doubling of the room temperature yield strength up to values around 100 ksi. The yield strengths of the as-cold worked bars ranged from 191 to 205 ksi (1317 to 1413 MPa), and the cold-worked + age-hardened bars ranged from 199 to 206 ksi (1372 to 1420 MPa). In these material conditions, C-22HS also exhibits excellent ductility and fracture toughness of _150 ft-lbs (_203 J) from -300ºF to +550ºF (-149 to 288°C). The C - 22HS alloy is presently being tested for Navy Subsafe high strength fastener approval. An important feature of the C-22HS alloy in the age-hardened condition is that the alloy retains excellent corrosion resistance. Both alloys C-86 and C-22HS have excellent potential for all marine and military applications where excellent strength, toughness and corrosion resistance are required. In addition to the nickel alloy just discussed, NITRONIC® 50HS (UNS S20910) Stainless Steel provides a combination of corrosion resistance and strength not found in any other commercial material available in its price range. As a result, the use of this alloy for boat shafting is significantly increasing for commercial and naval shipping. Superior corrosion resistance, high yield strength, exceptionally low magnetic permeability and outstanding cryogenic properties define this alloy usefulness for boat shafting.

scholarly journals Effect of Particle Size on Microstructure and Element Diffusion at the Interface of Tungsten Carbide/High Strength Steel Composites

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4164 ◽  
Author(s):  
Hongmei Zhang ◽  
Hongnan Li ◽  
Ling Yan ◽  
Chao Wang ◽  
Fangfang Ai ◽  
...  
Keyword(s):  
Particle Size ◽  
Tungsten Carbide ◽  
High Strength Steel ◽  
Average Particle Size ◽  
High Strength ◽  
Average Particle ◽  
Micro Hardness ◽  
Vacuum Sintering ◽  
Element Diffusion ◽  
Average Grain Size

The microstructure and micro-hardness of tungsten carbide/high strength steel (WC/HSS) composites with different particle sizes were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), ultra-high temperature laser confocal microscopy (UTLCM) and micro-hardness testing. The composites were prepared by cold pressing and vacuum sintering. The results show that WC density tends to increase as the average grain size of WC decreases and the micro-hardness of WC increases with the decrease of WC particle size. The micro-hardness of WC near the bonding interface is higher than that in other regions. When the particle size of WC powder particles is 200 nm, a transition layer with a certain width is formed at the interface between WC and HSS, and the combination between the two materials is metallurgical. The iron element in the HSS matrix diffuses into the WC structure in contact with it, resulting in a fusion layer of a certain width, and the composite interface is relatively well bonded. When the average particle size of WC powder is 200 nm, W, Fe and Co elements significantly diffuse in the transition zone at the interface. With the increase of WC particle size, the trend of element diffusion decreases.

scholarly journals Tool wear estimation in turning of Inconel 718 based on wavelet sensor signal analysis and machine learning paradigms

2020 ◽  
Vol 14 (5-6) ◽  
pp. 693-705
Author(s):  
Tiziana Segreto ◽  
Doriana D’Addona ◽  
Roberto Teti
Keyword(s):  
Machine Learning ◽  
Tool Wear ◽  
Inconel 718 ◽  
Signal Analysis ◽  
Elevated Temperatures ◽  
Wavelet Packet ◽  
Research Work ◽  
High Strength ◽  
Signal Features ◽  
Tool Wear Estimation

AbstractIn the last years, hard-to-machine nickel-based alloys have been widely employed in the aerospace industry for their properties of high strength, excellent resistance to corrosion and oxidation, and long creep life at elevated temperatures. As the machinability of these materials is quite low due to high cutting forces, high temperature development and strong work hardening, during machining the cutting tool conditions tend to rapidly deteriorate. Thus, tool health monitoring systems are highly desired to improve tool life and increase productivity. This research work focuses on tool wear estimation during turning of Inconel 718 using wavelet packet transform (WPT) signal analysis and machine learning paradigms. A multiple sensor monitoring system, based on the detection of cutting force, acoustic emission and vibration acceleration signals, was employed during experimental turning trials. The detected sensor signals were subjected to WPT decomposition to extract diverse signal features. The most relevant features were then selected, using correlation measurements, in order to be utilized in artificial neural network based machine learning paradigms for tool wear estimation.

Ultra-High Strength Steel Hot Stamping Technology and Devices

2014 ◽  
Vol 1063 ◽  
pp. 237-243
Author(s):  
Zhong De Shan ◽  
Qin Tai Yan ◽  
Chao Jiang ◽  
Wen Juan Rong
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
Hot Stamping ◽  
Research Work ◽  
High Strength ◽  
Parameters Optimization ◽  
Systematic Research ◽  
China Academy ◽  
Ultra High Strength Steel ◽  
Vehicle Structure

Ultra High Strength Steel (UHSS) hot stamping technology is a special process which can enhance the steel tensile strength to 1500MPa. Appling this technology in producing vehicle structure parts can make car lighter and safer. In China there are more and more automobile enterprises adopt this technology. To master and extend the skill, China Academy of Machinery Science & Technology (CAM) have done systematic research, such as the strengthen mechanism of the steel, hot stamping key devices designing, forming and quenching integrated mould designing, stamping process parameters optimization, etc.. By now, CAM has mastered the mass production technology of vehicle parts, which can guarantee its shape and tensile strength, and produced such typical parts as door-beam, B pillar, etc.. The paper is an introduction of the research work and achievement about UHSS hot stamping developed by CAM.

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