In this work, Cu/1060Al bimetallic composite materials manufactured by high-temperature free-oxygen rolling process are reported. The results show that with the increase of rolling passes, the ...microstructure of Cu and 1060Al gradually extends and elongates in the rolling direction, and the interface that has few compounds is dominated by mechanical bonding. It is worth noting that layered fracture occurs during the tensile process. After annealing, the interface changes from mechanical bonding to metallurgical bonding, and the layered fracture is alleviated under the traction of the interface layer. With the increase of annealing time and temperature, the thickness of the interface compounds gradually increase, and the interface compounds from the copper layer to the aluminum layer are Cu9Al4, CuAl and CuAl2, respectively. Annealing at 350 °C for 2 h exhibits the best comprehensive performance, a tensile strength of 138 MPa and an elongation of 64 %. Tensile behavior in the rolled state and annealed state has been discussed based on failure theory, and compound growth after annealing has been analyzed on account of the theories of dynamics and thermodynamics.
In this work, Cu/Al8011/Al1060 trilayered composite with an ultrathin copper layer was fabricated successfully by the hybrid process of cast-rolling and hot-roll-bonding. The effects of heat ...treatment were investigated on the microstructure and mechanical behavior of the composite. The results showed that annealing temperatures above 300 °C led to the formation of new intermetallic compounds that joined their initial counterparts. Also, the interface growth was fast above 340 °C. It was found that the annealing temperature of 320 °C led to the optimal tensile properties of the composite. Through rolling, hard-brittle IMCs imposed intense plastic strains on the surrounding regions, resulting in further grain refinement of both metals in the vicinity of the interface. Although the kernel average misorientation of the trilayered composite was almost identical with the Cu/Al8011 bimetal, its amount was considerably decreased after heat treatment, as the distorted structure changed into a nearly strain-free one using the restoration phenomenon. The SEM-based in-situ tensile test showed that crack initiation occurred within the IMCs and propagated into the Cu strip, leading to its early fracture. However, the strength-displacement curve during in-situ tensile deformation did not decrease significantly due to the ultrathin copper layer.
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•Cu/Al8011/Al1060 trilayered composite was studied systematically after annealing treatment.•Through rolling, a continuous nonuniform interface of Cu/Al8011 bimetal broke.•The use of heat treatment led to the integration of new IMCs of the Cu/Al interface with the previous one.•The composite optimal tensile properties were achieved at an annealing temperature of 320 °C.•Crack initiation occurred inside the IMCs and propagated into the copper layer.
This paper dealt with the combined processing of roll-casting and hot-rolling to fabricate high-performance Cu/Al8011/Al5052 composite with ultrathin copper thickness. It was shown that the ...intermetallic compounds formed at the Cu/Al interface include Al4Cu9, AlCu, and Al2Cu from the copper side, respectively, in which the CuAl phase has the lowest thickness due to its the high diffusion activation energy. Also, Al2Cu, due to having the lowest amount of Gibbs free energy, was initially formed at the interface, followed by the Al4Cu9 and AlCu phases. Although the room-temperature tensile strength of the trilayered composite is close to each other in both directions, the elongation to failure in the rolling direction is about 37% better than that of the transversal direction. Furthermore, no clear slip bands were observed in the uniform plastic deformation zone of the stress-strain curve during the high-temperature tensile tests compared to the room-temperature counterparts. Despite the decrease in tensile strength with increasing test temperature, this composite shows good tensile behavior at temperatures below 200 °C due to the pure shear fracture mode.
•Cu/Al8011/Al5052 composite with ultrathin copper thickness was fabricated by roll-casting and hot-rolling.•Both interfaces of the manufactured composite were metallurgically well-bonded.•Copper is the first layer to fracture during tensile deformation.•The uniform interface of Cu and Al8011 is split into several parts in the trilayered composite.
High-performance, ultra-low Cu layer thickness ratio pure Cu/8011 Al alloy/1060 Al alloy (Cu/8011/1060, for short) clads were first fabricated by roll casting and then roll bonding. The effects of ...rolling reduction rates on the microstructural evolutions and mechanical properties of Cu/8011/1060 clads during the roll-bonding process have been systematically investigated. Results show that the continuous but unequal-thickness intermetallic compound (IMC) layer is fractured after roll bonding. The fracture location is mainly at the transition zone between type I and type II IMCs or in the interiors of type I and type II IMCs. The IMCs are identified as Al
4
Cu
9
, AlCu and Al
2
Cu. The Cu layer thickness ratio decreases from 13.7 to 4.1 pct after roll bonding. The Cu/8011/1060 clads prepared at the rolling reduction rate of 47 pct have the best comprehensive mechanical performance with an ultimate tensile strength (UTS) of 135.7 MPa and elongation (EL) of 25.5 pct. Two different tensile fracture modes are observed for Cu/8011/1060 clads fabricated at different rolling reduction rates.
Three kinds of ester base oils (D85, D100, D115), dodecyl alcohol, dodecyl acid, butyl stearate as oiliness agents, and thiophosphate, fatty alcohol phosphates and dibutyl phosphate as extreme ...pressure agents were used to prepare and investigate the tribological properties of rolling oils for cold rolled laminated Cu/Al composite sheet by an orthogonal experiment, and lubrication performances of the rolling oils were studied through rolling experiments. Surface roughness and the interface of Cu/Al composite sheet were analyzed. The results show that the optimum tribological properties of the rolling oil is compose of D100 as basic oil, butyl stearate as oiliness agent and the compound ratio of fatty alcohol phosphates and thiophosphate of 3:1 as extreme pressure antiwar agent. The PB value reaches 1020 N, the coefficient of friction is 0.0795. Basic oil is the main factor of rolling capacity. The rolling oil contented D115, showed the best rolling capacity while the minimum thickness was only 0.045mm. The addition of butyl stearate improved the surface quality of both copper and aluminum side of the rolled stripes and make the sheet surface roughness decreased. After cold rolling, new composite interface, which is clear and tightly bound replaced the brittle mesophase.
In order to meet the demand of electronic and heat-radiating devices for CuAl composite the rolling-cladding technology for Cu-Al thin sheet was developed. The corresponding roll-cladding technology ...was optimized by the experiments. The varying regularity of thickness ratio in the rolling process of Cu-Al thin sheet was studied. The change in the Cu-Al interface was investigated by adopting different annealing technologies. The results show that the critical rolling reduction rate for AlCu cladding decreases with increasing the thickness proportion of Cu. The reduction rate of Al and Cu is proportional to total reduction rate. With the increase of the rolling reduction rate of Al and Cu, the reduction rate of Cu and Al also increases. Annealing can enhance the bending performance of the thin sheet. However, when the annealing temperature is too high, the hard and brittle intermetallic compounds form at the interface of Cu and Al, which will deteriorate the bonding strength of Cu-Al cladding sheet.
Scutellaria (
HUANG QIN) (Lamiaceae), which includes about
350 species commonly known as skullcaps, is widespread in Europe, the United States and East Asia. Some species are taken to clear away the ...heat-evil and expel superficial evils in traditional Chinese medicine (TCM). The present paper reviews the ethnopharmacology, the biological activities and the correlated chemical compounds of
Scutellaria species. More than
295 compounds have been isolated, among them flavonoids and diterpenes. Studies show that
Scutellaria and its active principles possess wide pharmacological actions, such as antitumor, anti-angiogenesis, hepatoprotective, antioxidant, anticonvulsant, antibacterial and antiviral activities. Currently, effective monomeric compounds or active parts have been screened for pharmacological activity from Scutellaria
in vivo and
in vitro. Increasing data supports application and exploitation for new drug development.
Scutellaria (Lamiaceae) includes about
350 species commonly known as skullcaps, it is widespread in Europe, the United States and East Asia. Some species have been widely used as local medicine for thousands years. Review on the ethnopharmacological, phytochemical, and pharmacological literatures indicated extracts and monomer compounds from
Scutellaria have great potential to cure cancer, hepatitis, HIV-1, etc.
Background
The human lip vermilion, also known as the red lip, is important to the quality of life and has long attracted the attention of cosmetic researchers. However, there is limited existing ...literature on the physiological characteristics and age‐related alterations in the human vermilion.
Objective
We aim to provide an overview of the physiological characteristics and age‐related alterations in the human vermilion.
Methods
This article is a result of previous research. We conducted a literature search using various academic databases such as Google Scholar, Web of Science, and PubMed. Our findings provided a comprehensive understanding of the physiological characteristics and age‐related changes of the human lip vermilion.
Results
The human lip vermilion has a unique structure and physiological characteristics, and during the aging process, a few changes may occur in the human lip vermilion.
Conclusion
Understanding the human lip vermilion's physiological characteristics and age‐related changes can provide key information for the future innovation of lip vermilion care products. Further investigations are necessary to reach a consensus on the physiological characteristics and age‐related alterations in the human vermilion.
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•1D MWO4 (M = Mn, Co, Cd) nanomaterials were synthesized by electrospinning method.•CoWO4 nanotubes exhibited superior efficiency in degrading BPA under UV–Vis–NIR light.•The ...wide-spectrum responses mechanism for MWO4 (M = Mn, Co, Cd) were explained by DFT.
Broadening the absorption region to near-infrared (NIR) light is critical for the photocatalysis due to the larger proportion and stronger penetration of NIR light in solar energy. In the present paper, one-dimensional (1D) MWO4 (M = Mn, Co, and Cd) materials synthesized by electrospinning technique, were studied by combining the density functional theory (DFT) with experiment results, which possessed the enhanced light absorption capability within the range of 200–2000 nm. It was proved that in the ultraviolet–visible (UV–Vis) region, the absorption bands of CoWO4 and MnWO4 samples were attributed to the metal-to-metal charge transfer mechanism, while the absorption of CdWO4 sample may be referable to the ligand-to-metal charge transfer mechanism. In the near-infrared (NIR) region, the absorption of CoWO4 and MnWO4 primarily originated from the d-d orbital transitions of Mn2+ and Co2+. The photocatalytic experimental results showed that the degradation rates for bisphenol A (BPA) over CoWO4, MnWO4, and CdWO4 photocatalysts under UV–Vis/NIR light irradiation for 140 min/12 h were 78.8 %/75.9 %, 23.8 %/21.3 %, 12.8 %/8.7 %, respectively. This research offers the novel insights into the precise construction of tungstate catalytic systems and contributes to the advancement of UV–Vis–NIR full spectrum photocatalytic technology, and lays a foundation for a cleaner and more environmental-friendly future.
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