Effects of solution temperature and cooling rate on microstructure and micro-hardness of a hot compressed Ti-6Al-4V alloy

Vacuum ◽  
2019 ◽  
Vol 159 ◽  
pp. 191-199 ◽  
Author(s):  
Y.C. Lin ◽  
Yi Tang ◽  
Xiao-Yong Zhang ◽  
Chao Chen ◽  
Hui Yang ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Solution Temperature ◽  
Micro Hardness

Effect of Solution Treatment on Microstructures and Mechanical Properties of Centrifugal Casting Al-Cu Alloy

2011 ◽  
Vol 306-307 ◽  
pp. 548-552
Author(s):  
Jun Li ◽  
Yan Wei Sui ◽  
Ai Hui Liu ◽  
Xin Zhao ◽  
Zhi Sun
Keyword(s):  
Mechanical Properties ◽  
Centrifugal Casting ◽  
Solution Treatment ◽  
Solution Time ◽  
Solution Temperature ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Alloy Casting ◽  
Cu Alloy ◽  
Microstructures And Mechanical Properties

Al-Cu alloy castings are obtained in the vertical centrifugal field. The effects of solution treatment on the microstructures and mechanical properties of Al-Cu alloy casting were studied by OM, micro hardness tester and room temperature tension and compression test. The results show that, the strength, micro hardness and elongation percentage of Al-Cu alloy casting increase firstly and then decrease as the solution temperature increases, and the mechanical properties reach the maximum values as the solution temperature increases to 530°C. As solution time increasing, the mechanical properties of Al-Cu alloy casting increase firstly and then decrease. When the solution time is up to 6 hours, the mechanical properties reach maximum value.

Effects of solution temperature and cooling rate on α phases and mechanical properties of a forged Ti-55511 alloy

2019 ◽  
Vol 6 (11) ◽  
pp. 1165h2 ◽  
Author(s):  
Y C Lin ◽  
Li-Hua Wang ◽  
Qiao Wu ◽  
Yi-Wei Xiao ◽  
Hao Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Solution Temperature

scholarly journals The Effect of Cooling Rate in Molten Salt Electro-Carburisation Process

2012 ◽  
Vol 576 ◽  
pp. 264-267 ◽  
Author(s):  
Nancy J. Siambun ◽  
Willey Y.H. Liew ◽  
George Z. Chen ◽  
Daniel A. Jewell ◽  
Yeo K. Beng
Keyword(s):  
Mild Steel ◽  
Molten Salt ◽  
Optical Microscopy ◽  
Cooling Rate ◽  
Molten Carbonate ◽  
Micro Hardness ◽  
Salt Mixture ◽  
Voltage Range ◽  
New Process ◽  
Martensite Structure

In the recent development of a new process of electro-carburisation of mild steel in 800 °C molten carbonate based salts, further investigation has been carried out to study the effects of the cooling rate after the electro-carburisation process. In the process, the mild steel to be carburised was made the cathode and an inert SnO2 as anode. Salt mixture of Na2CO3-NaCl (mole ratio 4:1) was used as the electrolyte, and the process was carried out at voltage range of 1.0 to 2.5 V for 60 minutes, and thereafter cooled at certain rate. As revealed by the optical microscopy, the microstructural changes in samples that have been electro-carburised and thereafter cooled either rapidly or naturally in air, were featured by the increase of the carbon rich in the martensite structure at the expense of the original ferrite phase near the surface of the samples. Micro-hardness profiles measured from the surface to the centre of the electro-carburised sample presented clear evidence of carbon penetration as a function of the electrolysis voltage, and significant effects of cooling rate after the electro-carburisation process.

Study on CCT Curve and Microstructure Evolution of HRB500E

2013 ◽  
Vol 470 ◽  
pp. 699-702
Author(s):  
Peng Tian ◽  
Zhi Yong Zhong ◽  
Rui Guo Bai ◽  
Xing Li Zhang ◽  
Quan Li Wang ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Microstructure Evolution ◽  
Theoretical Basis ◽  
High Strength ◽  
Micro Hardness ◽  
Cooling Process ◽  
Controlled Cooling ◽  
Steel Rebar ◽  
Cct Curve ◽  
Hardness Change

The microstructure evolution and hardness change were studied for vanadium containing high strength seismic rebar HRB500E at different cooling rates. The experimental results showed that bainite and martensite gradual emerged with the increasing cooling rate and resulted in an increasing micro-hardness. The cooling rate should be controlled at 0.5°C/s to 7°C/s to ensure good performances of steel rebar. The CCT curve of HRB500E measured with the inflation method and metallographic-Hardness method could provide the theoretical basis for controlled cooling process.

Influence of Cooling Rate on the Microstructures and Properties of a Nb-Ti-Mo Steel

2012 ◽  
Vol 152-154 ◽  
pp. 14-17
Author(s):  
Hai Long Yi ◽  
Yang Xu ◽  
Zhen Yu Liu ◽  
Guo Dong Wang
Keyword(s):  
Tensile Strength ◽  
Cooling Rate ◽  
High Strength ◽  
Strengthening Mechanisms ◽  
Micro Hardness ◽  
Cooling Process ◽  
Ultra Fast Cooling ◽  
Fast Cooling ◽  
Cooling Technology ◽  
Strength And Toughness

A Nb-Ti-Mo high strength steel was selected at two different cooling rates through ultra-fast cooling process, and its microstructures and strengthening mechanisms were analyzed. The results show the size of ferrite was decreased and the amount of bainite and micro-hardness were increased with increasing of cooling rate through thermal simulation. The UFC technology can improve the yield and tensile strength 25MPa and 35MPa, respectively, compared with conventional TMCP. The microstructure of this steel is mainly ferrite and good strength and toughness are caused by the refinement of ferrite and fine precipitates. Ultra-fast cooling technology improves the strength and toughness of this steel effectively.

scholarly journals Investigation of Micro Hardness, Cooling Rate and Microstructure of ATIG Welded samples of Al-SiC composite

2018 ◽  
Vol 151 ◽  
pp. 01002 ◽  
Author(s):  
Sivachidambaram Pichumani ◽  
Raghuraman Srinivasan ◽  
Venkatraman Ramamoorthi
Keyword(s):  
Cooling Rate ◽  
Heat Affected Zone ◽  
Weld Zone ◽  
Correlation Study ◽  
Tig Welding ◽  
Constant Current ◽  
Micro Hardness ◽  
Micro Structure ◽  
Fine Grain ◽  
Hardness Values

Activated TIG welding has been performed on Al – 8% SiC composite 5mm plate with various fluxes such as Al2O3, MnO2, CaO, MgO, SiO2 & TiO2, to study & analyze the Microstructure, Micro hardness and cooling rate. Correlation study between micro hardness, microstructure and cooling rate for Constant Current TIG welding and Activated TIG welding on Al-SiC composite are also carried out to analyze the relation between the effect of cooling rate on microstructure & the effect of microstructure on micro hardness. The experimental results of ATIG welding on Al-SiC composite shows fine grain weld microstructure on ATIG – SiO2 & ATIG – TiO2, which results in higher micro hardness. Micro hardness values are taken in different locations of weld surface at 1mm, 2mm & 3mm below the weld surface and the same is also observed along the weld zone to heat affected zone upto 12mm for the center of the weldment. Minimum micro hardness values found in ATIG – MnO2, ATIG – CaO & ATIG – MgO are due to intermediate micro structure between coarse and fine in heat affected zone. ATIG – Al2O3 weld zone & heat affected zone and heat affected zone of ATIG – MnO2, ATIG – CaO & ATIG – MgO shows coarse microstructure leading to reduction in micro hardness value. Cooling rate for the different CCTIG & ATIG welding are recorded and correlation between the micro structures are studied. Coarse micro structure in weld zone and heat affected zone have least cooling rate whereas fine micro structure in weld zone resulted at higher cooling rate. Heat affected zone strongly depends on temperature gradient between the weld center and weldment’s heat affected zone.

Precipitation Within a Precipitate—Nickel-Rich Alloys of Nickel, Aluminum and Titanium

1971 ◽  
Vol 29 ◽  
pp. 202-203
Author(s):  
J. M. Oblak ◽  
B. H. Kear ◽  
G. R. Leverant
Keyword(s):  
Phase Boundary ◽  
Cooling Rate ◽  
Single Phase ◽  
Solution Temperature ◽  
Ti Alloy ◽  
Nickel Aluminum ◽  
Solvus Temperature ◽  
The Matrix ◽  
Lower Temperature

Figure 1 shows how a precipitate of γ might form within a precipitate of γ' in a given Ni-Al-Ti alloy. The alloy reverts to single phase fcc γ on heating above the solvus temperature TS. Upon aging at T1 an LI2 γ' Ni3 (Al,Ti) phase of composition is formed and is in equilibrium with a γ matrix of composition. . If the alloy is subsequently aged at a lower temperature T2, not only does additional γ' form within the matrix, but γ can also precipitate within γ', provided that the γ' phase boundary is as represented.In this study a Ni-10.7Al-5.1Ti (at. %) alloy was air cooled from a solution temperature of 2250°F to form coarse γ' particles. The cooling rate was sufficiently rapid that equilibrium was not. achieved at temperatures corresponding to T2 in Figure 1. Samples were then aged for 16 hours at l400°F and their microstructure examined. As evident in Figure 2(a,b), the large γ' particles contained small plate-like precipitates after aging and these appeared to lie on {100} planes.

Influence of Cooling Rate on Phase Transformation of a α+β Titanium Alloy

2016 ◽  
Vol 849 ◽  
pp. 327-331
Author(s):  
Yue Fei ◽  
Xin Nan Wang ◽  
Guo Qiang Shang ◽  
Jing Li ◽  
Li Wei Zhu ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Phase Transformation ◽  
Cooling Rate ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Cooling Rates ◽  
X Ray ◽  
Lamellar Structures ◽  
Optical Micrograph ◽  
Α Phase

Effect rules of cooling rate on phase transformation and microstructure of a α+β titanium alloy were studied by thermal dilatometer method. Specimens under different cooling rates from 0.05°C/s to 2.5°C/s were analyzed by using X-ray diffraction (XRD), optical micrograph (OM) and Vickers micro-hardness. The results showed that the starting temperature of β to α phase transformation gradually decreased with the increase of cooling rate. The finishing temperature of β to α phase transformation firstly decreased and then increased with the increase of cooling rate. The typical lamellar structures were observed under the cooling rates from 0.05°C/s to 0.2°C/s. The layer thickness of α phase became thinner and the precipitation content of α phase reduced under the cooling rate of 0.5°C/s. The α phase was fine acicular and the precipitation content of α phase reduced obviously under the cooling rate of 2.5°C. The effect rule of cooling rate on micro-hardness was that the value of micro-hardness firstly decreased and then increased with the cooling rate increasing.

Effect of Cooling Rate on Microstructure and Mechanical Property of Fe-6.5wt%Si Alloy

2016 ◽  
Vol 850 ◽  
pp. 571-574
Author(s):  
Jing Ye Jiao ◽  
Qi Zhao Shen ◽  
Ai Chao Cheng ◽  
Ren Fei Guo ◽  
Tie Tao Zhou
Keyword(s):  
Cooling Rate ◽  
Silicon Content ◽  
Melt Spinning ◽  
Laser Surface ◽  
Gas Atomization ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Surface Remelting ◽  
Microstructure And Mechanical Property

Due to its high silicon content, Fe-6.5wt%Si alloy has low iron loss and its magnetostriction is almost zero. And therefore Fe-6.5wt%Si alloy has good development prospect. However it has poor ambient temperature ductility and its cold rolling is very difficult. It’s important to study the effect of cooling rate on the microstructure and mechanical properties of Fe-6.5wt%Si alloy. In the present study the master alloy was melted and cooled through normalization, gas atomization, laser surface remelting and melt spinning. The microstructure, micro-hardness and X-ray diffraction were analyzed. The evolution of the microstructure at different cooling rate was summarized. The results indicated that under high cooling rate, the grain was obviously refined, and the microhardness decreased, but the change of phase was not obvious.

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