China
Africa
Explore chapters and articles related to this topic
The research status and prospect of cryogenic treatment on aluminum alloys
Published in Yigang He, Xue Qing, Automatic Control, Mechatronics and Industrial Engineering, 2019
The 2014 aluminum alloy has high strength and hardness, good plasticity and toughness as well as good forging, heat resistance and weldability, so it has been well applied in the aerospace field. With the rapid development of high-speed railway in recent years, 2014 aluminum alloy is often used in various parts of this industry. However, the service life of the parts is reduced because of its low corrosion resistance, which limits the range of the engineering application to varying degrees. To improve these shortcomings, Xu et al. (2014) studied 12 kinds of composite processes including cryogenic treatment; they discovered two important processes. One of them was that a solid solution treatment for 80 mins at 505°C with water cooling, plus a cryogenic treatment holding for 20h, followed by an aging treatment for 12h at 160°C. The second was a solid solution treatment for 80 mins at 505°C, water cooling plus an aging treatment for 12h at 120°C, followed by a regression treatment for 15 mins at 200°C, water cooling and an aging treatment for 12h at 160°C. The first process dealt with cryogenic treatment after water cooling, and when compared to the second process without cryogenic treatment, the hardness and corrosion resistance of the aluminum alloy was significantly improved. In addition to high strength and good heat resistance, 2024 aluminum alloy also has the advantages of low density. Therefore, it is often used for the structural parts of aircraft, such as covering, skeleton, rib beam and partition frame. The study by Wang et al. (2012) showed that 2024 aluminum alloy after cryogenic treatment not only reduced the residual stress of quenching and promoted the second phase precipitation, but also significantly improved fatigue and corrosion resistance performance.
Wear characteristics of sintered AA2014 with alumina and titanium di-Boride metal matrix composites
Published in International Journal of Ambient Energy, 2021
S. Jayavelu, R. Mariappan, C. Rajkumar
AA 2014 aluminum alloy and composite-II (95 wt% of AA2014 + 5 wt % of TiB2) have a higher sintered density when compared with composite-I.Presence of hard reinforcement titanium diboride particle in composite-II suppresses agglomeration and grain growth.Composite- II has the highest hardness value of 190 HRB than the AA2014 aluminum alloy and composite-I.Due to the lower coefficient of friction and higher wear resistance of composite-II, it will meet the requirements of automobile components’ production such as cylinder pistons.As the coefficient of friction reduces, it reduces the friction power (occurring due to wear and tear of moving parts), thereby the power of the engine increases, and lowers the fuel consumption and lubricating cost.
Prediction of mechanical properties and modeling on sliding wear behavior of LM25/TiC composite using response surface methodology
Published in Particulate Science and Technology, 2018
Stir casting process is applied for the fabrication of the aluminum/silicon carbide (SiC) MMCs for varied volume fractions of SiC and the improvement in the properties has been analyzed. The result shows that uniform distribution of the reinforcement particles in the matrix is attained for all volume fractions of SiC and it results in a great increase of hardness and impact strength (Singla et al. 2009). Aluminum/Aluminum nitride (AlN) MMC has been fabricated through the stir casting process and its microstructural and mechanical characteristics are investigated. The result reveals that there is good bonding between the matrix and the reinforcement, which significantly increases the hardness of the composite (Wahab, Daud, and Ghazali 2009). The tensile behavior of the aluminum 6063/SiC particulate reinforced MMC produced under different wt% (5, 10, 15 and 20) and different particle sizes (220, 300 and 400 mesh) through the liquid metallurgy route has been studied. It is observed from the results that the tensile strength increases with the increase in reinforcement size and wt% of the SiC particles (Meena et al. 2013). The mechanical properties of 2014 aluminum alloy/titanium carbide (TiC) MMC fabricated under in situ process are investigated and increase of hardness, yield strength and ultimate tensile strength (UTS) by 35%, 15% and 24%, respectively, was observed compared to that of the unreinforced aluminum alloy (Kumar, Mahapatra, and Jha 2012). Investigation on the tensile strength and hardness of hybrid aluminum/alumina (Al2O3)/boron carbide (B4C) MMC and unreinforced aluminum alloy fabricated under stir casting is carried out and the results revealed that tensile strength is higher in case of aluminum alloy whereas the hardness is higher for the aluminum hybrid composite (Vijaya Ramnath et al. 2014).