scholarly journals Influence of Heat Treatment on Biocorrosion and Hemocompatibility of Biodegradable Mg-35Zn-3Ca Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jeong-Hui Ji ◽  
Il-Song Park ◽  
Yu-Kyoung Kim ◽  
Sook-Jeong Lee ◽  
Tae-Sung Bae ◽  
...  

Mg-35Zn-3Ca (wt.%) alloy containing nontoxic and biocompatible Zn and Ca as alloying elements was prepared and subjected to heat treatment and artificial aging for different duration of time to reduce its rate of degradation. Solution heat treatment was performed at 310°C while artificial aging was performed at 170°C for 0, 2.5, 5.0, 7.5, and 10.0 h and they were designated as AT0, AT1, AT2, AT3, and AT4, respectively. The finest and most homogenous reticulum was observed on the surface of the AT2 group. The result of immersion test in Hank’s balanced salt solution (HBSS) showed that the corrosion rate of the AT2 group was 2.32 mg/(cm2day), which was significantly lower as compared to other groupsP<0.05. The hemolysis value was ≤5% in all groups, indicating no toxicity during short-term blood reaction.

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
Xin He ◽  
Qinglin Pan ◽  
Hang Li ◽  
Zhiqi Huang ◽  
Shuhui Liu ◽  
...  

Three different aging treatments including single-aging, delayed-aging, and pre-aging were carried out on 6082 extruded profiles after solution heat treatment, then their hardness, tensile strength, and microstructure were tested. The experimental results reveal that the properties and microstructure changes during single-aging. Based on this, the negative effects of room temperature delay and the results of short-term pre-aging treatments used in the experiment to improve this phenomenon have been concluded.


2011 ◽  
Vol 399-401 ◽  
pp. 17-20
Author(s):  
Wen Bin Yu ◽  
Zhi Qian Chen ◽  
Mang Zhang ◽  
Zhou Yu

The precipitation hardening response of as-cast Mg-8Yb-0.5Zr magnesium alloy was investigated in the present work. The microstructure evolution of the alloy illustrated that Mg2Yb intermetallic phase was dissolved by solution heat treatment at 520°C for 12 hours. An apparent precipitation hardening response in Mg-8Yb-0.5Zr was discovered after artificial aging at 150°C, with maximum hardness increment of about 80 percent at the peak condition. It was found that the precipitates of the alloy were in the shape of two conjoined cosh and globe about 50 nm, and precipitated preferentially on grain boundaries and dislocations.


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1552
Author(s):  
Chenxi Yang ◽  
Nikhil Gupta ◽  
Hanlin Ding ◽  
Chongchen Xiang

The improvement in corrosion resistance of WE43 was well realized by heat treatment. To study the influence of microstructure on the corrosion behavior of WE43 in as-cast and heat-treated conditions, an immersion test was employed with as-cast and heat-treated samples in the 3.5% NaCl solution. The corrosion rate and change of morphology were recorded and the corrosion behavior was further investigated by scanning electron microscopy (SEM). The results indicated that the corrosion rate of the WE43 alloy decreased after heat treatment. It was observed that the eutectic gradually damages the protective film on the surface of the as-cast WE43 in the process of corrosion, which further increases the corrosion rate. The Zr-rich phase formed a domed structure resulting in the adjacent area being further corroded. The Y-rich phase has little effect on the corrosion reaction.


2019 ◽  
Vol 25 (3) ◽  
pp. 281-285
Author(s):  
Dhanashekar MANICKAM ◽  
Senthil Kumar VELUKKUDI SANTHANAM

Aluminium alloys are subjected to heat treatment to increase the strength and corrosion properties. This paper aims to study the effect of heat treatment on the compression behaviour of A356 alloy under quasi static condition and barreling effect. The various heat treatments are: (i) solution heat treatment of 1 h at 540 °C + natural aging 0 h + artificial aging at 180 °C up to 5.5 h, (ii) solution heat treatment of 3 h at 540 °C + natural aging for 20 h + artificial aging at 180 °C up to 5.5 h, and (iii) solution heat treatment of 6 h at 540 °C + natural aging for 20 h + artificial aging at 180 °C up to 5.5 h. Specially to understand the influence of artificial aging at every 0.5 h up to 5.5 h, the specimens were heat treated. From the results, solutionizing for 1 hr have a better compression strength irrespective of the artificial aging. Natural aging had decreased the ductility but increased the strength property. Artificial aging had a significant effect on the compressive strength and peak strength were obtained at 4 h irrespective of solutionizing heat treatment. Compressive strength increased by 33 % for 1 h of solutionizing and 4 h of artificial aged specimen when compared to non-heat treated alloy. Two mathematical relations discussed in literature were used for calculating the radius of the barreled surface followed by validation. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20442


CORROSION ◽  
1963 ◽  
Vol 19 (5) ◽  
pp. 169t-179t ◽  
Author(s):  
WILLIAM E. KUHN

Abstract An investigation has been made of the influence of amount and distribution of precipitate phase on the corrosion kinetics of “low purity” zirconium in 20 percent hydrochloric acid at 200 C. It was found that minimum corrosion rates, coincident with minimum values of activation energy and frequency factor in the Arrhenius relationship, were obtained by solution heat treatment at 700 C followed by water quenching. Such heat treatment gave a corrosion rate equivalent to that of alpha annealed iodide zirconium. A maximum corrosion rate was obtained by a beta solution treatment at 890 C followed by water quenching, whereas beta solution treatment at 1000 C gave sharply reduced corrosion rates. Nature of distribution of the precipitate phase profoundly influenced corrosion rate. A discontinuous pattern of intergranular and transgranular globular particles was substantially less deleterious than the same amount of impurity phase finely disseminated throughout the microstructure. The results of the investigation are discussed in terms of the possible roles of chlorine and hydroxyl ions in the corrosion mechanism. Relative effects on corrosion kinetics of statistical distributions of active sites (each characteristic of lattice configurations produced by lattice defects, solute atoms and precipitation phenomena) are also considered.


2016 ◽  
Vol 877 ◽  
pp. 109-113
Author(s):  
Seong Ho Ha ◽  
Young Ok Yoon ◽  
Shae K. Kim

Effects of Si addition on the microstructure, fluidity and tensile property of Al-5/7mass%Mg alloys with Mg+Al2Ca master alloy as Mg raw material were investigated in this study. With 7 mass%Si addition, the fluidity was remarkably improved in both Al-5Mg and Al-7Mg alloys. With increasing the Si content, the amount of the eutectic phases was increased in the microstructures. As a result of the tensile test, there was a drastic reduction in elongation with increasing Si content. Al-5Mg-7Si alloy showed a significant improvement of strength after solution heat treatment and artificial aging.


2013 ◽  
Vol 749 ◽  
pp. 54-60
Author(s):  
Yao Qiang Gan ◽  
Lei Lu ◽  
Da Tong Zhang ◽  
Wei Wen Zhang ◽  
Yuan Yuan Li

A high strength Al-Cu-Mg alloy was prepared by squeeze casting. The effects of squeeze casting and heat treatment on the microstructures and mechanical properties of the alloy were studied. It was found that squeeze casting refined the microstructure and reduced the micro-segregation markedly, and also accelerated the diffusion process of solute atoms during solution heat treatment. Tensile strength and elongation of squeeze casting alloy were much higher than those of gravity casting alloy under both the as-cast and heat-treated conditions. In addition, the Al-Cu-Mg alloy prepared by squeeze casting showed good natural aging response, and the naturally-aged alloy possessed a slightly lower tensile strength but better elongation compared to full artificial aging. After solution heat treatment at 495 for 9h and further natural aging for 48h or artificial aging at 190 for 6h, the tensile strength of squeeze casting alloy reached to 472MPa and 475MPa, respectively, and the elongation was 18.9% and 12.7% accordingly. Based on the experimental results, the mechanism of microstructural evolution of squeeze casting Al-Cu-Mg alloy during heat treatment was discussed, and the effect of squeeze casting on the kinetics of solute diffusion and aging precipitation was studied.


2018 ◽  
Vol 8 (4) ◽  
pp. 3113-3115
Author(s):  
S. M. Rajaa ◽  
H. A. Abdulhadi ◽  
K. S. Jabur ◽  
G. R. Mohammed

This work investigates the influence of artificial aging and solution heat treatment on the hardness and tensile strength (mechanical properties) of Al 6061-T6 alloy. For this investigation, several aluminum 6061-T6 alloy specimens were prepared following the ASTM 176000 recommendations. The prepared specimens were heated for 1 hour at 500ºC before being water-quenched. The procedure for artificial aging was performed for 1, 2, 3, and 4 hours at 190ºC before being slowly cooled in air. Several mechanical and characterization studies were performed on the treated specimens, including an investigation on their microstructure, tensile strength, hardness, and X-ray diffraction pattern. From the results, the strength and hardness properties of the specimens were found to be generally improved, even as the best features were obtained after 2 hours of artificial aging.


2007 ◽  
Vol 558-559 ◽  
pp. 159-164 ◽  
Author(s):  
Jae Hyung Cho ◽  
Y.M Jin ◽  
Hyoung Wook Kim ◽  
Suk Bong Kang

Variations in microstructure and mechanical properties of ZK60 alloy sheets were investigated with aging time. ZK60 alloy sheets with a thickness of 1mm were prepared from a casting ingot followed by homogenization and warm-rolling. Artificial aging process after solution heat treatment (T6) affected both hardness variations and precipitates distributions with aging time. Hardness variations were related to precipitates, i.e. rod-shaped ( 1 β ′ ) or disc shaped ( 2 β ′ ) particles. Rod-shaped ( 1 β ′ ) precipitates mainly consist of Mg and Zn without Zr.


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