Thermodynamic Calculation and Experimental Study on Complex Phase Steel

2013 ◽  
Vol 716 ◽  
pp. 349-354 ◽  
Author(s):  
Jun Jie Zhao ◽  
Yan Lin He ◽  
Na Qiong Zhu ◽  
Mei Zhang ◽  
Lin Li

Using Thermo-calc software, transformation points as well as bainite starting temperature of the CP steel studied in the present work were calculated. Based on the measured CCT curve, the steels were treated at different conditions using Gleeble-3500 thermal simulation tester. To study the effects of cooling conditions on mechanical properties and microstructure of the steels after austenization, a combination of tensile tests at room temperature, SEM and TEM techniques was applied. Results showed that effective design of chemical composition and heat treatments can be achieved using Thermo-Calc software. The CP steel with carbon equivalent of 0.43% achieved B/M complex microstructure when austenized at 975 °C and followed by isothermal holding at bainitic transformation temperature of 450 °C. The tensile strength is 843.29 MPa and the elongation is 14.28%.

Author(s):  
Rafael Luis Menezes Freitas ◽  
Celio Costa ◽  
Erica Gervasoni Chaves ◽  
Sylvia Teixeira

This study presents the mechanical properties evaluation of two commercial grades of PVDFs, which were extruded with the same parameters but with different cooling temperatures. After processing, stress relaxation with 7% strain was imposed and tensile properties were measured. The cooling temperature after extrusion were 4°C, 23°C and 80°C. Then, the PVDFs were submitted to stress relaxation at 23°C and 7% strain. The as processed and after relaxation samples were characterized by FTIR, XRD, DSC and tensile tests at 23°C. The stress relaxation at 23 °C resulted in no change in volume fraction of crystallinity for PVDF A and B. The XRD and FTIR, for both PVDFs, showed that the crystalline phases were the same, for all cooling conditions and did not change after the stress relaxation. The tensile properties at room temperature showed that the yield stress was a little affect by the cooling temperature, while Young’s Modulus and yield strain were insensible to the cooling temperature. After the stress relaxation, these three tensile properties were slightly affected for both grades.


2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.


2010 ◽  
Vol 654-656 ◽  
pp. 819-822
Author(s):  
Genki Kikuchi ◽  
Hiroshi Izui ◽  
Yuya Takahashi ◽  
Shota Fujino

In this study, we focused on the sintering performance of Ti-4.5Al-3V-2Mo-2Fe (SP-700) and mechanical properties of SP-700 reinforced with titanium boride (TiB/SP-700) fabricated by spark plasma sintering (SPS). TiB whiskers formed in titanium by a solid-state reaction of titanium and TiB2 particles were analyzed with scanning electron microscopy and X-ray diffraction. The TiB/SP-700 was sintered at temperatures of 1073, 1173, and 1273 K and a pressure of 70 MPa for 10, 30, and 50 min. The volume fraction of TiB ranged from 1.7 vol.% to 19.9 vol.%. Tensile tests of TiB/SP-700 were conducted at room temperature, and the effect of TiB volume fraction on the tensile properties was investigated.


2017 ◽  
Vol 17 (4) ◽  
pp. 73-78 ◽  
Author(s):  
F. Kahrıman ◽  
M. Zeren

Abstract In this study, Al-0.80Mg-0.85Si alloy was modified with the addition of 0.3 wt.-% zirconium and the variation of microstructural features and mechanical properties were investigated. In order to produce the billets, vertical direct chill casting method was used and billets were homogenized at 580 °C for 6 h. Homogenized billets were subjected to aging practice following three stages: (i) solution annealing at 550 °C for 3 h, (ii) quenching in water, (iii) aging at 180 °C between 0 and 20 h. The hardness measurements were performed for the alloys following the aging process. It was observed that peak hardness value of Al-0.80Mg-0.85Si alloy increased with the addition of zirconium. This finding was very useful to obtain aging parameters for the extruded hollow profiles which are commonly used in automotive industry. Standard tensile tests were applied to aged profiles at room temperature and the results showed that modified alloy had higher mechanical properties compared to the non-modified alloy.


2012 ◽  
Vol 735 ◽  
pp. 136-139
Author(s):  
Guo Feng Wang ◽  
Shao Song Jiang ◽  
Zhen Lu ◽  
Kai Feng Zhang

Superplasticity of nanocrystalline materials is a hot spot in the field of scientific research. In this paper, Ni-Co alloy was produced through pulse electrodeposition. Tensile tests were carried out to study the room temperature strength, high temperature plasticity. The superplastic formability under complex stress was evaluated through the superplastic bulging tests. The tests were studied through the methods of resistance heating and furnace temperature heating. The maximum ratios of height and diameter with different heating method were compared. Fracture behavior and microstructure were observed by the method of SEM.


Author(s):  
Christopher D. Newton ◽  
Jonathan P. Jones ◽  
Adam L. Chamberlain ◽  
Martin R. Bache

The complex structural architecture and inherent processing artefacts within ceramic matrix composites combine to induce inhomogeneous deformation and damage prior to ultimate failure. Bulk measurements of strain via extensometry or even localised strain gauging will fail to characterise such inhomogeneity when performing conventional mechanical testing on laboratory scaled coupons. The current research project has, therefore, applied digital image correlation (DIC) techniques to the room temperature axial assessment of a SiCf/SiC composite under static and ratchetted loading. As processed SiCf/SiC panels were subjected to detailed X-ray computed tomography (XCT) inspection prior to specimen extraction and subsequent mechanical testing. In situ DIC strain measurements were taken throughout the period of room temperature monotonic and ratchet style tensile tests. Contemporary acoustic emission (AE) signals were also recorded to indicate significant damage events and the onset of ultimate failure. Data from these separate monitoring techniques were correlated to indicate the sensitivity or otherwise to pre-existing artefacts within the as received CMC panels.


DYNA ◽  
2016 ◽  
Vol 83 (195) ◽  
pp. 77-83 ◽  
Author(s):  
María José Quintana Hernández ◽  
José Ovidio García ◽  
Roberto González Ojeda ◽  
José Ignacio Verdeja

The use of Cu and Ti in Zn alloys improves mechanical properties as solid solution and dispersoid particles (grain refiners) may harden the material and reduce creep deformation. This is one of the main design problems for parts made with Zn alloys, even at room temperature. In this work the mechanical behavior of a Zn-Cu-Ti low alloy is presented using tensile tests at different strain rates, as well as creep tests at different loads to obtain the value of the strain rate coefficient m in samples parallel and perpendicular to the rolling direction of the Zn strip. The microstructure of the alloy in its raw state, as well as heat treated at 250°C, is also analyzed, as the banded structure produced by rolling influences the strengthening mechanisms that can be achieved through the treatment parameters.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5856
Author(s):  
Pragya Mishra ◽  
Pia Åkerfeldt ◽  
Farnoosh Forouzan ◽  
Fredrik Svahn ◽  
Yuan Zhong ◽  
...  

Laser powder bed fusion (L-PBF) has attracted great interest in the aerospace and medical sectors because it can produce complex and lightweight parts with high accuracy. Austenitic stainless steel alloy 316 L is widely used in many applications due to its good mechanical properties and high corrosion resistance over a wide temperature range. In this study, L-PBF-processed 316 L was investigated for its suitability in aerospace applications at cryogenic service temperatures and the behavior at cryogenic temperature was compared with room temperature to understand the properties and microstructural changes within this temperature range. Tensile tests were performed at room temperature and at −196 °C to study the mechanical performance and phase changes. The microstructure and fracture surfaces were characterized using scanning electron microscopy, and the phases were analyzed by X-ray diffraction. The results showed a significant increase in the strength of 316 L at −196 °C, while its ductility remained at an acceptable level. The results indicated the formation of ε and α martensite during cryogenic testing, which explained the increase in strength. Nanoindentation revealed different hardness values, indicating the different mechanical properties of austenite (γ), strained austenite, body-centered cubic martensite (α), and hexagonal close-packed martensite (ε) formed during the tensile tests due to mechanical deformation.


2015 ◽  
Vol 18 (4) ◽  
pp. 162-169
Author(s):  
Thao Song Thanh Nguyen ◽  
Nhung Thi Tuyet Le

An experimental investigation into ratcheting strain and stress-strain hysteresis loop in stress-controlled cyclic tensile tests at room temperature was performed to determine the effect of loading frequency on the cyclic mechanical behavior of highdensity polyethylene (HDPE). It was found that frequencies ranging from 0.01 Hz up to 1 Hz mostly affects the accumulated strain over related time scales (i.e that of the cycle itself) and not over long time scale (i.e. during the full test). In addition, the higher the frequency is, the more closed and vertical the loops are. Furthermore, the frequency affects only on the kinetics of stabilization of ratcheting strain but not on one of hysteresis loop.


2010 ◽  
Vol 654-656 ◽  
pp. 2126-2129 ◽  
Author(s):  
Yuichi Nakahira ◽  
Tomonari Inamura ◽  
Hiroyasu Kanetaka ◽  
Shuichi Miyazaki ◽  
Hideki Hosoda

Effect of nitrogen (N) addition on mechanical properties of Ti-Cr-Sn alloy was investigated in this study. Ti-7mol%Cr-3mol%Sn was selected and less than 0.5wt% of N were systematically added. The alloys were characterized by optical microscopy, X-ray diffraction analysis and tensile tests at room temperature. The apparent phase was β (bcc) phase, whereas the presence of precipitates was confirmed in 0.5wt%N-added alloy only which did not exhibit sufficient cold workability. The grain size was not largely affected by N addition being less than 0.5wt%. Tensile tests revealed that less than 0.5wt%N addition improves the strength which is due to the solution hardening by interstitial N atoms.


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