Effect of Cryogenic Treatment on Mechanical Properties and Microstructures of 3102 Al-Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 845-848 ◽  
Author(s):  
Xian Quan Jiang ◽  
Ning Li ◽  
Hong He ◽  
Xiu Jin Zhang ◽  
Chun Chi Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Breaking Strength ◽  
Cryogenic Treatment ◽  
Al Alloy ◽  
Deep Cryogenic Treatment ◽  
Transmission Electron ◽  
Elongation To Failure ◽  
Shrinkage Force ◽  
Very Low Temperature

The mechanical properties and microstructures of different state cryogenic treatment 3102 Al-foil, such as H19，H26 or O state, were studied by tensile testing, optical metalloscopy (OM) and transmission electron microscope(TEM). The results showed that, after deep cryogenic treatment, the strength of H19 state increased and the elongation to failure decreased. In the same time, the yield strength increased and breaking strength decreases and the elongation decreased dramatically for O state, but, for H26 state, the strength and elongation increased dramatically, which correspond to the properties of this state at low temperatures. OM and TEM observation showed cryogenic treatment caused by the fibrous grains broken down and many grains with the size of 0.1~3μm These fine equiaxial grains can improve the strength and elongation of the Al-foil. On the contrary, the atomic shrinkage force slips high density dislocations into interface of the grains and forms terraces and fissure in it. That leads to the elongation decrease and the interface been broaden at very low temperature. The grain size of O state with cryogenic treatment is larger than without cryogenic treatment. As a result, the synthetic mechanical properties of H26 state improved by the way of cryogenic treatment, but the H19 state and O state should avoid use and put at low temperatures.

scholarly journals SIMULTANEOUSLY ENHANCING MECHANICAL PROPERTIES AND ELECTRICAL CONDUCTIVITY OF CU-CR ALLOY PROCESSED BY ECAP AND DCT

2020 ◽  
Vol 26 (4) ◽  
pp. 161-165
Author(s):  
Zhu Qi Chu ◽  
Kun Wei ◽  
Li Yang ◽  
Qing Du ◽  
Wei Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Tensile Strength ◽  
Dislocation Density ◽  
Vacancy Concentration ◽  
Cryogenic Treatment ◽  
Shear Direction ◽  
Deep Cryogenic Treatment ◽  
Angular Pressing ◽  
Elongation To Failure

Mechanical properties and electrical conductivity of Cu-0.5%Cr alloy were simultaneously enhanced by combing the equal channel angular pressing (ECAP) and deep cryogenic treatment (DCT). The effect of DCT on the microstructure and properties of Cu-0.5%Cr alloy prepared by ECAP was investigated. The results show that the grains were elongated and refined along the deformation shear direction, and the dislocation density increased significantly by ECAP deformation. After the subsequent DCT, the grains were further refined, and at the same time, the dislocation density was further increased. With the increase of passes of ECAP, the microhardness and tensile strength of Cu-0.5%Cr alloy increased significantly, but the elongation to failure and electrical conductivity decreased slightly. After the DCT, the microhardness, electrical conductivity, tensile strength and elongation to failure of the Cu-0.5%Cr alloy were improved. After the ECAP (four passes) and DCT (12 h), the tensile strength, elongation to failure and electrical conductivity reached 483 MPa, 17.6% and 29%IACS respectively. The improvement of tensile properties could be attributed to the increase of dislocation density and grain refinement. The electrical conductivity was improved by the DCT due to the decrease of vacancy concentration.

scholarly journals The Influence of Deep Cryogenic Treatment (DCT) on the Mechanical Behaviour of Aluminium Metal Matrix Composites

2019 ◽  
Vol 9 (1) ◽  
pp. 1425-1431
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Mechanical Behaviour ◽  
Metal Matrix ◽  
Cryogenic Treatment ◽  
Al Alloy ◽  
Matrix Composites ◽  
Mass Percentage ◽  
Deep Cryogenic Treatment ◽  
Aluminium Metal

The outcome of cryogenic treatment (CTT) on the mechanical behaviour of Al alloy LM 25, LM25+5% fly ash and LM25+10%fly ash composites was investigated. Cryogenic treatments were performed with threedifferent soaking periods (0 hr (Untreated), 12hr, 24hr) ata constant cryogenic temperature of -196°C. After the CTT, the mechanical behaviour of the materials was measured. It is obvious that LM25+10% fly ash composites exhibitbetter mechanical properties than the LM25 and LM25+10% fly ash composites.As cryogenic soaking period increases mechanical properties of the MMCs tend to increase too. The effect of fly ash mass percentage and cryogenic soaking period on the mechanical behaviour of materials was studied by using Taguchi and Analysis of Variance (ANOVA).

The effect of ageing duration on the mechanical properties of Al alloy 6061-garnet composites

2001 ◽  
Vol 215 (2) ◽  
pp. 113-119
Author(s):  
S C Sharma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Al Alloy ◽  
Destructive Testing ◽  
Transmission Electron ◽  
Heat Treated ◽  
The Matrix ◽  
Reinforcing Particle ◽  
Alloy 6061

A well-consolidated composite of Al alloy 6061 reinforced with 4, 8 and 12 wt% garnet was prepared by a liquid metallurgy technique, the composite was heat treated for different ageing durations (T6 treatment), and its mechanical properties were determined by destructive testing. The results of the study indicated that, as the garnet particle content in the composites increased, there were marked increases in the ultimate tensile strength, compressive strength and hardness but there was a decrease in the ductility. There was an improvement in the tensile strength, compressive strength, and hardness with ageing due to precipitation. Precipitation in Al alloy 6061, with and without garnet particulate reinforcement, was studied using transmission electron microscopy. The fracture behaviour of the composites was altered significantly by the presence of garnet particles and the crack propagation through the matrix, and the reinforcing particle clusters resulted in final fracture.

scholarly journals Effect of Cryogenic Treatment on Microstructure and Wear Resistance of Carburized 20CrNi2MoV Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 808 ◽  
Author(s):  
Binzhou Li ◽  
Changsheng Li ◽  
Yu Wang ◽  
Xin Jin
Keyword(s):  
Electron Microscopy ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Cryogenic Treatment ◽  
Wear Test ◽  
Deep Cryogenic Treatment ◽  
Transmission Electron ◽  
Conventional Heat Treatment ◽  
Carburizing Process ◽  
Ball On Disc

This paper investigated the response of carburized 20CrNi2MoV steel to cryogenic treatment including microstructure and wear resistance. Two cryogenic treatment methods including cryogenic treatment at −80 °C (CT) and deep cryogenic treatment at −196 °C (DCT) as well as conventional heat treatment (CHT) were carried out after carburizing process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD) were employed for microstructure characterization. The wear resistance was investigated by ball-on-disc sliding wear test on a multi-functional tribometer. The results show that the wear resistance of the experimental steel has been improved by 17% due to CT and by 25.5% due to DCT when compared to CHT. This significant improvement in wear resistance after cryogenic treatment is attributed to the microstructural changes including the finer martensitic structure, the reduction of retained austenite and the development of fine and more numerous carbides. Among these factors, the precipitation of fine carbides plays a more prominent role in enhancing wear resistance.

Sign in / Sign up

Export Citation Format

Share Document