The properties and heat treatment of Ti?Cr and Ti?Cr?Al alloys

1963 ◽  
Vol 5 (2) ◽  
pp. 87-94
Author(s):  
V. N. Moiseev
Keyword(s):  
Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1607
Author(s):  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Mohd Zaidi Omar ◽  
Armin Rajabi

Friction stir welding (FSW) is an alternative method to join aluminum (Al) alloys in a solid-state condition. However, the coarsening or dissolution of precipitation hardening phases in the welding zone causes strength reduction or softening behavior in the welded area of age-hardened Al alloys. Therefore, this research aimed to improve the mechanical properties of an FSW Al–Mg–Si alloy via post-weld heat treatment (PWHT) and the possibility of controlling the abnormal grain growth (AGG) using different welding parameters. FSW was performed with different rotational and travel speeds, and T6 heat treatment was carried out on the FSW samples as the PWHT. The results showed a decrease in the strength of the FSW samples compared with that of the base material (BM) due to the dissolution of precipitation hardening particles in the heat-affected zone. However, the emergence of AGG in the microstructure after the T6-PWHT was identified as the potential event in the microstructure of the PWHT samples. It is found that the AGG of the microstructure in similar joints of Al6061(T6) was governed by the welding parameters. The results proved that PWHT was able to increase the tensile properties of the welded samples to values comparable to that of Al6061(T6)-BM. The increased mechanical properties of the FSW joints were attributed to a proper PWHT that resulted in a homogeneous distribution of the precipitation hardening phases in the welding zones.


1999 ◽  
Vol 14 (5) ◽  
pp. 1760-1770 ◽  
Author(s):  
H. G. Jiang ◽  
H. M. Hu ◽  
E. J. Lavernia

The synthesis of nanocrystalline Fe, Fe–4 wt% Al, and Fe–10 wt% Al solid solutions by SPEX ball milling has been studied. The microstructural evolution during ball milling, as well as subsequent heat treatment, has been characterized. The results demonstrate that ball milling promotes the formation of αFe–4 wt% Al and αFe–10 wt% Al solid solutions by reducing the activation energy of these alloys and generating thermal energy during this process. For Fe–10 wt% Al powders milled for various time intervals up to approximately 20 min, the FeAl intermetallic compound is formed. For alloys annealed at temperatures ranging from 600 to 1000 °C, the addition of 10 wt% Al to Fe significantly enhances the thermal stability of the nanocrystalline Fe–Al alloys. Interestingly, the addition of Al within the range of 4–10 wt% seems to have little effect on the thermal stability of these alloys annealed under the same conditions. Also, the thermal stability improves for alloys milled in air as opposed to those processed using Ar.


1983 ◽  
Vol 28 ◽  
Author(s):  
J.W. Sears ◽  
B.C. Muddle ◽  
H.L. Fraser

ABSTRACTPowders of Al alloy 7091 have been consolidated by means of dynamic compaction. The dependence of density and hardness on projectile velocity has been determined. The resulting as-compacted material has been characterized using analytical transmission electron microscopy and evidence of interparticle melting observed. The microstructural responseof the compacted material to heat treatment at 523 and 723°K has been investigated.


2019 ◽  
Vol 374 ◽  
pp. 21-31 ◽  
Author(s):  
Kamaal S. Al-Hamdani ◽  
James W. Murray ◽  
Tanvir Hussain ◽  
Adam T. Clare

2019 ◽  
Vol 961 ◽  
pp. 118-125
Author(s):  
Muhammad Syukron ◽  
Zuhailawati Hussein ◽  
Abu Seman Anasyida

The combination of heat treatment, addition of grain refiner and ECAP processing is used to improve mechanical properties and wear resistance of A356 Al alloys with 1.5 wt.% TiB2. The alloys were grouped into as-cast and pre-ECAP annealing. The alloys were characterized with hardness and wear testing, optical microscopy and SEM. The ECAP processing was done through BA route for 4 passes and it improved hardness, distribution of TiB2 and Si particles in the aluminium matrix and increased wear resitance of pre-ECAP annealing specimen.


2021 ◽  
Vol 15 (57) ◽  
pp. 350-358
Author(s):  
Hiralal S. Patil ◽  
D. C. Patel

Magnesium alloys have generated renewed interest as a light alloys; replacing some conventional structural materials for weight reduction in applications like aerospace, automotive and electronics industries. In interior components and powertrains, cast alloys are widely used and represent more than 99% of magnesium alloys used today, whereas only a few wrought products are used. Mostly in automotive applications, Mg-engine block can noticeably reduce the weight and consequently its fuel consumption and environmental impact. Due to solid-state precipitates, these alloys are strong in nature and are produced by an age-hardening heat treatment process. In the present work the age hardening behavior of the as cast Mg–Zn–Al alloys (ZA85 alloy) in the composition of 8 wt. %Zn, 5 wt. %Al has been investigated. Through the differential thermal analysis (DTA) studies, it has been found out that dissolution temperature of ternary eutectic precipitates is present in the alloy. Based on the DTA results, the as cast samples have been solutionised at 360 °C temperature for different intervals of time. Solutionising time has been optimized from the enthalpy values of un-dissolved precipitates. The solution treated samples have been then aged at temperature of 180° C for different time intervals. From the peak hardness values, the ageing conditions have been optimized.


Author(s):  
Sagil James ◽  
Ambarneil Roy

Abstract Among the different commercially used Aluminum (Al) alloys, the 7000 series offers some of the highest mechanical properties making them the material of choice for several critical engineering applications. These Al alloys often required to undergo a heat treatment (HT) process to enhance their mechanical and metallurgical properties to the desired levels. Currently, there is a growing need to find the optimal operational parameters for the HT process of Al 7000 series alloys. The operators have to resort to a start/stop approach, while intermittently evaluating and testing the mechanical properties until the desired level is reached. Among the various steps, aging is the final and often the longest step in the HT process. Consequently, the age soak time parameter needs to be narrowed to the smallest possible operating range for industrial applications. This study aims to experimentally optimize the age soak time of Al 7000 series alloys (7050-T74 and 7075-T73) by measuring its hardness, electrical conductivity (EC), fatigue properties. The study found that the optimal age soak times for 7050-T74 and 7075-T73 Al alloys are between 24–27 hours and 22–24 hours, respectively. The results of the study are subsequently confirmed using the grain flow and grain direction analysis. The results of this study are crucial in extending the applications of Al 7000 series alloys in several critical engineering industries.


2015 ◽  
Vol 226 ◽  
pp. 91-94
Author(s):  
Rafał Michalik ◽  
Bartosz Chmiela

Zn-Al alloys are mainly used due to their tribological properties as an alternative material for bronze, cast irons and aluminum in a bearings and as a construction material. Particular interesting is Zn-40Al-3Cu alloy due to its features. Improvement of the alloy’s features can be obtained by silicon addition, plastic working, heat treatment – solutionizing and ageing. In the article have been shown results of the ZnAl22Cu3 alloy examination as - cast and subjected solutionizing and ageing 385 oC/10h + 175 oC/1h and 385 oC/10h + 175 oC/10h. The scope of examination included: structure testing using scanning microscope, X - ray microanalysis, hardness test. There was found significant decrease of hardness of the tested alloy. Structural examinations have shown that initially in the structure were visible precipitates reach in aluminum and copper. Also were visible precipitates reach in zinc. With increasing time of soaking at 175 oC precipitates reach in aluminum and copper disappeared.


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