Dependence of the static and cyclic crack resistances of large forged semifinished products from aluminum alloys 1933 and V95 on the cooling rate in quenching

1995 ◽  
Vol 37 (6) ◽  
pp. 243-247
Author(s):  
G. L. Shneider
Keyword(s):  
2020 ◽  
Vol 993 ◽  
pp. 203-207
Author(s):  
Wei Min Ren ◽  
Zi Yong Chen ◽  
Zhi Lei Xiang ◽  
Li Hua Chai

Refining grain plays an important role in improving the mechanical properties of aluminum alloys. However, the conventional casting method with a slow cooling rate can be easy to cause coarseness of the microstructure and serious segregation. In this paper, the rapid solidification of Al-Zn-Mg-Cu alloy was prepared by the single-roller belt method. The alloy strip was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness test to study the microstructure and properties of the rapidly solidified aluminum alloy. The results show that the roller speed was an important parameters affecting the formability of the alloy. When the roller speed was 15 m/s, the aluminum alloy produced a thin bandwidth of 5 mm and a thickness of 150 um. As the rotation speed of the roller increased, the cooling rate of the melt increased, and the microstructure of the rapidly solidified Al-Zn-Mg-Cu aluminum alloy strip improved in grains refinement. Compared with the conventionally cast Al-Zn-Mg-Cu aluminum alloys, the Al-Zn-Mg-Cu aluminum alloys prepared by rapid solidification showed much finer crystal grains, and enhanced solid solubility of alloying elements with less precipitation of second phase and high hardness.


2006 ◽  
Vol 519-521 ◽  
pp. 549-554 ◽  
Author(s):  
Seong Taek Lim ◽  
Yong Yun Lee ◽  
Il Sang Eun

Recent 7xxx aluminum alloys have been designed for the finite use of thick semiproduct with contolled amount of constituent phases which mostly evolve during ingot preheat. In this study, the effects of constitutional change and preheat conditions of 7175 and 7050 type alloys on the evolution of constituent phases [M-, T-, S-phase and dispersoid] are presented. The constiuents evolve depending on the constitutional effect, primarily the change of Zn:Mg ratio, preheat condition comprising temperature and cooling rate following preheat. T- and M-phase are reprecipitated during cooling after preheat, depending on the alloy constitutions. S-phase is evolved depending on the constitution and preheat temperature, rather than preheat cooling rate. Prominent precipitation temperature interval of constituents are discussed in view of quaternary phase evolutions. In addition, evolutions of dispersoids together with M-phase are discussed. Specific alloy designs and preheat conditions could provide controlled microstructures for the thick 7xxx semiproducts.


2014 ◽  
Vol 67 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Angela de Jesus Vasconcelos ◽  
Cibele Vieira Arão da Silva ◽  
Antonio Luciano Seabra Moreira ◽  
Maria Adrina Paixão de Sousa da Silva ◽  
Otávio Fernandes Lima da Rocha

Al-Sn alloys are widely used in tribological applications. In this study, thermal, microstructural and microhardness (HV) analysis were carried out with an Al-5.5wt.%Sn alloy ingot produced by horizontal directional transient solidification. The main parameters analyzed include the growth rate (V L) and cooling rate (T R).These thermal parameters play a key role in the microstructural formation. The dendritic microstructure has been characterized by primary dendritic arm spacing (λ1) which was experimentally determined and correlated with V L, and T R. The behavior presented by the Al-5.5wt.%Sn alloy during solidification was similar to that of other aluminum alloys, i.e., the dendritic network became coarser with decreasing cooling rates, indicating that the immiscibility between aluminum and tin does not have a significant effect on the relationship between primary dendritic arm spacing and the cooling rate. The dependence of the microhardness on V L, T R and λ1 was also analyzed. It was found that for increasing values of T R, the values of HV decrease. On the other hand, the values of HV increase with increasing values of λ1.


2021 ◽  
Vol 97 (1) ◽  
pp. 3-8
Author(s):  
A.V. Nogovitsyn ◽  
◽  
V.L. Lakhnenko ◽  
I.R. Baranov ◽  
◽  
...  

Today, in the world, it is widely used in the production of aerospace equipment, sea vessels, railway transport and cars have high-strength aluminum alloys Al-Zn-Mg-Cu (for example, B95) and alloys of medium Al-Mg (AMg5), Al-Si-Mg ( AD35) and increased strength Al-Cu-Mg (D16). An in-depth study of individual factors that directly affect the structure of the work piece can be crucial for improving product quality during further thermomechanical processing. The article defines data on the grain size of the primary phase of aluminum alloys depending on the cooling rate of castings of various aluminum alloys (AD35, B95, D16, AMg5). It is shown that an increase in the cooling rate from 2-8 ° C / s to almost 1000 ° C / s leads to a decrease in the grain size of the фазы-phase from 200 μm to 10-40 μm. As a result of the experiments carried out in the work, the intervals of hardening of the investigated aluminum alloys were determined. It is shown that aluminum alloys containing copper in the chemical composition (≥1%) have a significantly wider crystallization range, in particular, B95 (1600C) and D16 ( 1320C). The samples of strip used in this work from high-strength aluminum alloys obtained by roll casting, to expand the range of investigated cooling rates, have a homogeneous structure with a uniform distribution of phase components, which ensures high functional properties of rolled products from high-strength, heat-strengthened alloys of the Al-Cu and AL-Zn systems. The obtained data of the research results can be recommended for use in the development of the domestic technology of roll casting of high-strength aluminum alloys. Keywords: High-strength aluminum alloys, roll casting, cooling rate, solidification time, differential thermal analysis, grain size.


2020 ◽  
Vol 41 (6) ◽  
pp. 793-803
Author(s):  
F. Zhang ◽  
C. Zhang ◽  
S.-M. Liang ◽  
D. C. Lv ◽  
S. L. Chen ◽  
...  

1967 ◽  
Vol 89 (1) ◽  
pp. 40-48
Author(s):  
R. L. Wells

The objective of this investigation was to establish the factors governing weldability and to determine their effects with sufficient quantitativeness to be able to predict cracking. A test was developed that permits variation of three factors deduced to be important—strain, maximum temperature, and cooling rate—so that welding conditions can be duplicated on a parent-metal specimen. Predictions of cracking during cooling of aluminum alloy panels containing 4.5 and 8 weight percent copper were made from results of this test and observed to be very accurate.


2018 ◽  
Vol 243 ◽  
pp. 00022 ◽  
Author(s):  
Vladimir Valikhov ◽  
Nikolay Kahidze ◽  
Anton Khrustalyov ◽  
Ilya Zhukov ◽  
Alexander Vorozhtsov

A357 and 6082 aluminum alloys strengthened by aluminum nitride nanoparticles were obtained. The process of crystallization of the A357-0.5 wt% Al2O3 and 6082-0.5 wt% Al2O3 alloys was studied under conditions of varying the cooling rate. The A357 and 6082 aluminum alloy structure and hardness were analyzed for the Al2O3 content from 0 to 1 wt%.


Author(s):  
V B Deev ◽  
E S Prusov ◽  
M Shunqi ◽  
E H Ri ◽  
T A Bazlova ◽  
...  

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