JOURNAL OF MATERIALS SCIENCE
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2023
·Vol. 58
·期 22
·9382-9393
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IF 4.5
Wang Bingying,Zhang Keke,Gao Yijie,Liu Peng,Liu Bo,Zhang Zhansheng
The trend toward miniaturized and highly integrated chip packaging has created a pressing need for lead-free solders with high strength, toughness, and conductivity. In this paper, we designed a scheme of Al 2 O 3 -modified nanomaterial-reinforced low silver Sn1.0Ag0.5Cu (SAC105) solder matrix. To begin with, a novel amorphous carbon and nickel core–shell structure plating modified on Al 2 O 3 (C/Ni/Al 2 O 3 ) were prepared by the electroless plating method. Then, the nano-C/Ni/Al 2 O 3 particle as reinforcement phase was mixed into the matrix solder alloy by ultrasonic vibration stirring. Finally, the morphology and relationship between coated carbon, deposited nickel and original solder interface were analyzed. The microstructure and main properties of the modified solders were also investigated. The experimental results suggested that amorphous carbon and nickel film were prepared on the surface of Al 2 O 3 by electroless plating method. The outer layer of nano-Al 2 O 3 was coated with non-uniform thickness of nickel and carbon coatings. The mass percentage of amorphous carbon was about 3.50%. Adding C/Ni/Al 2 O 3 (0–0.5%) into the SAC105 solder matrix resulted in a gradual increase in conductivity and wettability. The strength and toughness of the modified solder alloy improved as well with the adjunction of reinforced phase. The tensile fracture surface exhibited from a mixture of ductile and brittle, characterized by dimples and cleavage surface, to a purely ductile mode consisting mainly of dimples.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Xiaoxuan Pang,Yajiang Xian,Wei Wang,Pengcheng Zhang
Aluminum matrix Boron carbide composites is an important thermal neutron shielding material. In order to prepare 12 wt% B 4 C/6061Al composite with higher mechanical properties by powder metallurgy method, the new composite reinforced by Nano-Al 2 O 3 particles was fabricated by hot isostatic pressing in the semi-solid temperature range. The tensile properties and strengthening effects of the composite were investigated in this research. The tensile stress-strain curve of the composites was tested by material testing machine, and the microstructure and tensile fracture morphology of composites were analyzed by scanning electron microscopy (SEM) and transmission electron microscopes (TEM). The results indicated that the tensile strength of the composite was greatly improved by the addition of Nano-Al 2 O 3 , but the elongation decreased obviously. Nano-Al 2 O 3 particles had seriously affected the microstructure and fracture morphology of the composite and lead to the more obvious brittle fracture characteristics . Strengthening mechanisms of Nano-Al 2 O 3 particles reinforced 6061Al/B 4 C composite have been discussed, which reveals that grain boundary strengthening mainly plays the most important role.
研究领域:
材料科学
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力学
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产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2020
·Vol. 35
·期 3
·514-519
·
IF 0.64
Liu Tingling,Pang Xiaoxuan,Xian Yajiang,Luo Hao,Zhang Pengcheng
Aluminum-matrix boron carbide (B 4 C p /Al) is a kind of neutron absorbing material widely used in nuclear spent fuel storage. In order to improve the tensile property of B 4 C p /Al composites, a new type of nano-Al 2 O 3 particle (Al 2 O 3np ) reinforced B 4 C p /Al + Al 2 O 3np composites were prepared by powder metallurgy method. The Monte Carlo particle transport program (MCNP) was used to determine the influence of Al 2 O 3np on the thermal neutron absorptivity of composites. The universal material testing machine and scanning electron microscope (SEM) were used to study the mechanical properties, microstructure and fracture morphology of B 4 C p /Al composites. The results indicated that the neutron absorption properties of B 4 C p /Al composites were not affected by the addition of nano-Al 2 O 3 particles in the range of 1 wt%–15 wt%. The addition of Al 2 O 3np can obviously reduce the grain size of B 4 C p /Al matrix metals thus improve the tensile strength of the composites. The addition threshold of Al 2 O 3np is about 2.5 wt%. Both B 4 C p and Al 2 O 3np change the fracture characteristics of the composites from toughness to brittleness, and the latter is more important.
研究领域:
材料科学
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核工程
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DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Xue Hu,Shusen Wei,Yipin Zhang,Qi Lin,Xueming Chen,Liang Cai,Hong Dong,Yanjiang Song,Zhirong Qu,Chuan Wu
Four mono-alkoxysilyl-terminated asymmetric siloxane oligomers and a dimethylvinylsilyl-terminated branched-chain structure siloxane oligomer were prepared by a series of reactions to improve the filling loads and dispersion of Al 2 O 3 particles in the polysiloxane matrix. Their influence on the surface modification of Al 2 O 3 particles and the viscosity of composite materials was investigated. When the branched-chain siloxane oligomer was not used, mono-trimethoxysilyl-terminated asymmetric siloxane oligomers exhibited the best modification effect on the Al 2 O 3 surface, and the silicone paste prepared by filling 70.8 vol% mixed-size Al 2 O 3 particles had the lowest viscosity. When the branched-chain siloxane oligomer was used, the filling load of the modified Al 2 O 3 particles could be further increased to 84.3 vol% under the synergistic effect of the mono-trimethoxysilyl-terminated asymmetric siloxane oligomers and the branched-chain siloxane oligomer. The viscosity of the silicone paste decreased with the increase in the polymerization degree of the dimethylsiloxane segment in the-mono trimethoxysilyl-terminated asymmetric siloxane oligomers. Meanwhile, the thermal conductivity of these silicone pastes also exhibited an increasing trend with the increase in the polymerization degree of the asymmetric siloxane oligomers. A thermal interface material with a thermal conductivity higher than 8.0 W/(m·K) was successfully prepared by using the asymmetric siloxane oligomers as the surface modification agent for Al 2 O 3 particles and the branched-chain siloxane oligomer as the fluidity modifier for silicone paste.
研究领域:
材料科学
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热管理技术
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2023
·
IF 5.2
Shaoxiang Xu,Meihua Zhu,Pengming Huang,Shengao Zheng,Yujie Qiao,Yuan Liang,Xiangshu Chen,Hidetoshi Kita
Nano-size titanium silicalites is difficult to be separate from the reaction solution, lamellar and homogeneous Ti-MWW zeolites are successfully formed a dense zeolite layers on α-Al 2 O 3 pellets by secondary hydrothermal synthesis in this study. Seeded crystals concentration and titanium source have significantly influences on the morphology, thickness and titanium active sites of Ti-MWW zeolites. Doping NH 4 F in the precursor synthesis solution could conducive to prepare macroscopically and anatase-free Ti-MWW zeolites layer on the outside of α-Al 2 O 3 pellets, and the thickness of the Ti-MWW zeolites layer is ca. 1 mm. Besides, catalytic performance of the supported Ti-MWW zeolites are significantly improved by NH 4 F. A fixed-bed reactor with the supported Ti-MWW zeolites are applied to catalyze phenol hydroxylation with hydrogen peroxide efficiently, and reaction time and temperature, amount of the supported Ti-MWW zeolites have obvious effects on the phenol conversion and dihydroxybenzene selectivity. When the actual mass of Ti-MWW zeolites to volume of reaction solution is only 10 g/L, the relative phenol conversion and dihydroxybenzene selectivity are 46.45% and 92.72% at 65 °C after 3 h, respectively.
研究领域:
催化
·
材料科学
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化学工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）