Effect of Processing Parameters on Intermetallic Phase Content and Impact Toughness for Super Duplex Alloy PM HIP Sandvik SAF 2507™

2019 ◽  
Keyword(s):  
Impact Toughness ◽  
Intermetallic Phase ◽  
Processing Parameters ◽  
Phase Content ◽  
Duplex Alloy

High-Yield Direct Synthesis of Mg2FeH6 from the Elements by Reactive Milling

2011 ◽  
Vol 170 ◽  
pp. 259-262 ◽  
Author(s):  
Daniel Rodrigo Leiva ◽  
André Castro De Souza Villela ◽  
Carlos de Oliveira Paiva-Santos ◽  
Daniel Fruchart ◽  
Salvatore Miraglia ◽  
...  
Keyword(s):  
Raw Materials ◽  
Low Cost ◽  
Direct Synthesis ◽  
Intermetallic Phase ◽  
Weight Ratio ◽  
Processing Parameters ◽  
High Yield ◽  
Reactive Milling ◽  
Complex Hydrides ◽  
Important Processing

Magnesium complex hydrides as Mg2FeH6 are interesting phases for hydrogen storage in the solid state, mainly due to its high gravimetric and volumetric densities of H2. However, the synthesis of this hydride is not trivial because the intermetallic phase Mg2Fe does not exist and Mg and Fe are virtually immiscible under equilibrium conditions. In this study, we have systematically studied the influence of the most important processing parameters in reactive milling under hydrogen (RM) for Mg2FeH6 synthesis: milling time, ball-to-powder weight ratio (BPR), hydrogen pressure and type of mill. Low cost 2Mg-Fe mixtures were used as raw materials. An important control of the Mg2FeH6 direct synthesis by RM was attained. In optimized combinations of the processing parameters, very high proportions of the complex hydride could be obtained.

Study on the Hot Processing Parameters-Impact Toughness Correlation of Ti-6Al-4V Alloy

2016 ◽  
Vol 25 (5) ◽  
pp. 1741-1748 ◽  
Author(s):  
Xiaohui Shi ◽  
Weidong Zeng ◽  
Yu Sun ◽  
Yuanfei Han ◽  
Yongqing Zhao
Keyword(s):  
Impact Toughness ◽  
Processing Parameters

Hysteresis modeling of porous SMA for drug delivery system designed and fabricated by the laser-assisted sintering

2013 ◽  
Vol 1569 ◽  
pp. 141-147 ◽  
Author(s):  
Igor V. Shishkovsky
Keyword(s):  
Drug Delivery ◽  
Phase Transformation ◽  
Drug Delivery System ◽  
Delivery System ◽  
Porous Scaffold ◽  
Selective Laser Sintering ◽  
Intermetallic Phase ◽  
Processing Parameters ◽  
Hysteresis Phenomenon ◽  
Temperature Hysteresis

ABSTRACTIn this report we develop a complete mathematical model for a porous scaffold from nitinol (NiTi – intermetallic phase) with a shape memory effect (SME), fabricated layerwise via the selective laser sintering (SLS) process. The operation of the SME bio-fluidic MEMS involves such physical process as a heat transfer, a phase transformation with a temperature hysteresis, stress-strain and electrical resistance variations accompanied the phase transformation. The simulations were conducted for the electro- and a thermo- mechanical hysteresis phenomenon, during the SME in the porous nitinol structures of the cylinder shape, which allow to formulate a recommendations for SLS. Previously done the temperature evolution of electrical resistivity was compared with our present calculations as a function of the laser-processing parameters for three dimensional nitinol samples. This model can be used for an estimation of a drug delivery system route during a porous phase volume changing.

Effect of Heat Treatment Processing Parameters on the Microstructure and Properties of Low-Carbon Cr-Ni-Mo Carburizing Bearing Steels

2015 ◽  
Vol 817 ◽  
pp. 231-237 ◽  
Author(s):  
Nan Zhang ◽  
Mao Sheng Yang ◽  
Shi Qing Sun
Keyword(s):  
Heat Treatment ◽  
Impact Toughness ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Processing Parameters ◽  
Bearing Steel ◽  
Low Carbon ◽  
Quenching Temperature ◽  
Tempering Temperature ◽  
The Impact

The low-carbon Cr-Ni-Mo carburizing bearing steel was tested with different heat treatment processes. Quenching-tempering temperature and cryogenic treatment (-73°C) wasstudied respectively onthe mechanical properties and microstructure.Results show thatthe increase of quenching temperature causes the micron-sized Cr-rich carbide re-dissolution and smaller quantity of retained austenite, makingthe strength and hardness of the tested steel increase and the impact toughness decrease. The tempering temperaturerising causesthe reduction of micro-residual stresses and smallerdegree of lattice distortion andlower dislocation density, resulting in the decrease of strength and the increase of impact toughness. Cryogenic treatment contributes to the refinement of martensite lath and precipitation of nanosized carbide and lowest quantity of retained austenite, improving the strength and impact toughness of the steel.The good comprehensive mechanical propertieswith the hardness of HRC41.3, tensile strength of 1413MPa,yield strength of 1168MPa, and impact toughness of 162J/cm2 can be obtainedby optimizing the heat treatment process parameters.

Crystal Structure Analysis of Cu-Zr Alloys by Convergent Beam Diffraction

1981 ◽  
Vol 39 ◽  
pp. 354-355
Author(s):  
A. F. Marshall ◽  
J. W. Steeds ◽  
D. Bouchet ◽  
S. L. Shinde ◽  
R. G. Walmsley
Keyword(s):  
Crystal Structure ◽  
Point Group ◽  
Intermetallic Phase ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Ion Milling ◽  
Composition And Structure ◽  
Unit Cells ◽  
Sputter Deposited ◽  
Convergent Beam

Convergent beam electron diffraction is a powerful technique for determining the crystal structure of a material in TEM. In this paper we have applied it to the study of the intermetallic phases in the Cu-rich end of the Cu-Zr system. These phases are highly ordered. Their composition and structure has been previously studied by microprobe and x-ray diffraction with sometimes conflicting results.The crystalline phases were obtained by annealing amorphous sputter-deposited Cu-Zr. Specimens were thinned for TEM by ion milling and observed in a Philips EM 400. Due to the large unit cells involved, a small convergence angle of diffraction was used; however, the three-dimensional lattice and symmetry information of convergent beam microdiffraction patterns is still present. The results are as follows:1) 21 at% Zr in Cu: annealed at 500°C for 5 hours. An intermetallic phase, Cu3.6Zr (21.7% Zr), space group P6/m has been proposed near this composition (2). The major phase of our annealed material was hexagonal with a point group determined as 6/m.

Microstructural Variations in Melt-Spun Rapidly Solidified Ribbons

1985 ◽  
Vol 43 ◽  
pp. 54-55
Author(s):  
L. A. Bendersky ◽  
W. J. Boettinger
Keyword(s):  
Solid State ◽  
Processing Parameters ◽  
Heat Extraction ◽  
Solid State Reactions ◽  
Careful Examination ◽  
Ion Milling ◽  
Melt Spun ◽  
Wheel Side ◽  
Rapidly Solidified ◽  
Heat Extraction Rate

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.

Structure of a new orthorhombic phase in NiTi: Mn shape memory alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 1000-1001
Author(s):  
Jenö Beyer ◽  
Lajos Tóth
Keyword(s):  
Martensitic Transformation ◽  
Structural Changes ◽  
High Vacuum ◽  
Intermetallic Phase ◽  
Orthorhombic Phase ◽  
Transformation Process ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Crystallographic Structures ◽  
Ternary Additions

The structural changes during reversible martensitic transformation of near-equiatomic NiTi alloys can best be studied in TEM at around room temperature. Ternary additions like Mn offer this possibility by suppressing the Ms temperature below RT. Besides the stable intermetallic phases (Ti2Ni, TiNi, TiNi3) several metastable phases with various crystallographic structures (rhombohedral, hexagonal, monoclinic, cubic) have also been reported to precipitate due to suitable annealing procedures.TiNi:Mn samples with 0.9 and 1.3 at% Mn were arc melted in argon atmosphere and homogenized at 948 °C for 72 hours in high vacuum in an infrared furnace. After spark cutting slices of 0.2 mm, TEM specimens were prepared by electrochemical polishing with the twin-jet technique in methanol - perchloric acid electrolyte. The TEM study was carried out in a JEOL 200 CX analytical electron microscope.In this paper a new intermetallic phase is reported which has been observed in both samples by TEM during the martensitic transformation process.

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