Effect of Heat Treatment Conditions on Multistage Martensitic Transformation in Aged Ni-rich Ti-Ni Alloys

2004 ◽  
Vol 842 ◽  
Author(s):  
Minoru Nishida ◽  
Toru Hara ◽  
Yasuhiro Morizono ◽  
Mitsuhiro Matsuda ◽  
Kousuke Fujishima
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Quartz Tube ◽  
Preferential Oxidation ◽  
Ni Alloys ◽  
Treatment Conditions ◽  
Precipitation Morphology

ABSTRACTIt has been demonstrated with systematic experiments that the appearance and disappearance of multistage martensitic transformation (MMT) in aged Ni-rich Ti-Ni alloys depend on the heat treatment conditions. No multistage transformation occurs when the evaporation of Ti and Ni and/or the preferential oxidation of Ti in the specimen are prevented and the purification of heat treatment atmosphere in an evacuated quartz tube is achieved. The heterogeneity in precipitation morphology of the Ti3Ni4 phase, which is responsible for the multistage transformation can be suppressed with the regulation of heat treatment atmosphere as mentioned above. We have concluded that the multistage martensitic transformation in aged Ni-rich Ti-Ni alloys is extrinsic in nature, and is an artifact during the heat treatment.

scholarly journals Effect of Heat Treatment on Microstructural Changes in Aluminium Bronze

2016 ◽  
Vol 61 (3) ◽  
pp. 1271-1276 ◽  
Author(s):  
J. Hájek ◽  
A. Kříž ◽  
O. Chocholaty ◽  
D. Pakuła
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Martensitic Transformation ◽  
Microstructural Changes ◽  
Treatment Conditions ◽  
Aluminium Bronze ◽  
Quench Test ◽  
Scanning Electron

Abstract This paper attempts to summarise the microstructural changes which take place in aluminium bronzes during heat treatment. Another objective of this study was to map the potential of a certain type of aluminium bronzes for undergoing martensitic transformation. The methods, which were chosen for assessing the results of heat treatment with regard to their availability, included measurement of hardness and observation of microstructure using light and scanning electron microscopy, Additional tools for evaluation of microstructure comprised measurement of microhardness and chemical analysis by EDS. An important part of the experiment is observation of microstructural changes in the Jominy bar during the end-quench test. Upon completing experiments of this kind, one can define the heat treatment conditions necessary for obtaining optimum properties. In addition, the paper presents important findings on how to improve the corrosion resistance of aluminium bronzes by special heat treatment sequences.

Influence of Mn Additions on the Thermoelastic and Pseudoelastic Behaviour of Cu-Ai-Ni Alloys

1994 ◽  
Vol 360 ◽  
Author(s):  
M.A. Morris ◽  
T. Lipe
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Activation Energies ◽  
Manganese Concentration ◽  
Ni Alloys ◽  
Two Phases ◽  
Mn Additions ◽  
Kinetics Of

AbstractThe transformation properties of Cu-Al-Ni alloys modified by the additions of boron and manganese have been interpreted by studying the reversibility and stability of the martensitic transformation as a function of heat treatment and of manganese concentration between 2 and 4 wt%. The alloy containing 2% Mn exhibits a lack of thermoelasticity due to a decrease of the degree of B2 order and supression of DO3 order during quenching and the increase of both types of order during annealing. From the determination of the activation energies responsible for the martensitic and reverse transformations, we have deduced that, in both cases, the kinetics of the transformation are controlled by an atomic jump at the interface between the two phases.

scholarly journals Effect of Heat Treatment Conditions on the Morphology of α Phase and Mechanical Properties In Ti-10V-2Fe-3Al Titanium Alloy/ Wpływ Warunków Obróbki Cieplnej Na Morfologie Fazy α I Własności Mechaniczne W Stopie Tytanu Ti-10V-2Fe-3Al

2014 ◽  
Vol 59 (4) ◽  
pp. 1269-1273 ◽  
Author(s):  
R. Bogucki ◽  
K. Mosór ◽  
M. Nykiel
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
Martensitic Transformation ◽  
Volume Fraction ◽  
Heating Time ◽  
Α Phase ◽  
Microstructure And Mechanical Properties ◽  
Treatment Conditions

Abstract The influence of heat treatment on the microstructure and mechanical properties was studied in the Ti-10V-2Fe-3Al titanium alloy for two heat treatment schemes (α + β) and β + (β + α), which resulted in different morphologies of the α phase. Scheme I resulted in the α-phase of globular morphology, whose volume fraction did not change much during annealing. Scheme II led to obtaining a needle-like α-phase, whose amount increased together with heating time. The phenomenon of stress-induced martensitic transformation was observed in the material with needle-like morphology annealed for 15 and 30 min. Longer times of annealing effected in the decay of that transformation, provided the volume fraction of α-phase exceeded 50%.

Effect of heat treatment atmosphere on the multistage martensitic transformation in aged Ni-rich Ti–Ni alloys

2006 ◽  
Vol 438-440 ◽  
pp. 489-494 ◽  
Author(s):  
K. Fujishima ◽  
M. Nishida ◽  
Y. Morizono ◽  
K. Yamaguchi ◽  
K. Ishiuchi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Ni Alloys

On the defects of enamel coatings

2019 ◽  
pp. 145-150
Author(s):  
T. O. Soshina ◽  
V. R. Mukhamadyarovа
Keyword(s):  
Heat Treatment ◽  
Surface Tension ◽  
Electron Microscope ◽  
Enamel Coating ◽  
Surface Defects ◽  
Linear Expansion ◽  
Corrosion Properties ◽  
Treatment Conditions ◽  
Mechanical And Corrosion Properties ◽  
Coefficient Of Linear Expansion

The defects destroy the integrity of the enamel, and the paper examines the influence of the physical-mechanical and corrosion properties of frits and heat treatment on the defectiveness of the enamel coating. The surface defects were scanned by electron microscope. It has been established that the defectiveness of enamel coatings depends on the melting index, temperature coefficient of linear expansion, surface tension of the frits, and heat treatment conditions. When burning rate of the enamel coating decreases, the fine-meshed structure of the enamel changes, and the size of the defects decreases.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

Effect of copper incorporation on phase transformation behavior of electroless nickel–phosphorous coating and its effect on the tribological behavior

2020 ◽  
pp. 146442072098160
Author(s):  
Abhijit Biswas ◽  
Suman Kalyan Das ◽  
Prasanta Sahoo
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Tribological Behavior ◽  
Electroless Nickel ◽  
Two Phase ◽  
Microstructural Changes ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Higher Temperature ◽  
Effect Of Copper

The microstructural changes of electroless Ni–P–Cu coating at various heat-treatment conditions are investigated to understand its implications on the tribological behavior of the coating. Coatings are heat-treated at temperatures ranging between 200°C and 800 °C and for 1–4 h duration. Ni–P–Cu coatings exhibit two-phase transformations in the temperature range of 350–450 °C and the resulting microstructural changes are found to significantly affect their thermal stability and tribological attributes. Hardness of the coating doubles when heat-treated at 452 °C, due to the formation of harder Ni3P phase and crystalline NiCu. Better friction and wear performance are also noted upon heat treatment of the coating at the phase transformation regime, particularly at 400 °C. Wear mechanism is characterized by a mixed adhesive cum abrasive wear phenomena. Heat treatment at higher temperature (600 °C and above) and longer duration (4 h) results in grain coarsening phenomenon, which negatively influences the hardness and tribological characteristics of the coating. Besides, diffusion of iron from the ferrous substrate as well as greater oxide formation are noticed when the coating is heat-treated at higher temperatures and for longer durations (4 h).

Effect of Heat Treatment Conditions on the Properties of Nanoporous Glasses Activated by Gold Nanoparticles

2021 ◽  
Author(s):  
G. Yu. Shakhgil’dyan ◽  
A. A. Mikhailov ◽  
T. O. Lipat’eva ◽  
K. I. Piyanzina ◽  
E. A. Kolesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Gold Nanoparticles ◽  
Treatment Conditions
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