JOURNAL OF MATERIALS SCIENCE
·
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
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Chenguang Guo,Xingyu Li,Lin Zhang,Yuan Shi,Peng Zhang,Zichen Wei,En Mei,Zhongyou Que,Mingli Qin,Xuanhui Qu
Ultrafine-grained (UFG) VNbMoTaW refractory high entropy alloy (RHEA), reinforced with carbide particles, was prepared through a novel powder metallurgy route. Initially, pre-alloyed RHEA powder, characterized by body-centered cubic (BCC) phase, ∼88 nm particle size and good dispersity, was fabricated via a wet-chemical (WC) method. The high quality of the nano powder enabled low-temperature sintering with suppressed grain growth. Subsequently, a dense UFG VNbMoTaW RHEA bulk sample was fabricated by spark plasma sintering (SPS). It provided uniform microstructure with 99 % theoretical density and ∼320 nm grain size. The residual carbon from powder facilitated the precipitation of carbide phases in the sintering process. These carbide precipitates were identified by a high-entropy characteristic, ∼180 nm particle size and a volume fraction of 8.3 %, serving as effective reinforcing agents for the RHEA matrix. Benefiting from the high configurational entropy, ultrafine grain size, and precipitate phase, the bulk RHEA exhibited excellent mechanical properties in terms of a high hardness of 10.9 GPa and a compressive strength of 4.2 GPa with an acceptable strain of 10.7 %. We expect such a powder metallurgy route should also be applicable to other systems of RHEAs.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yingxuan Chen,Hongzhi Cui,Leigang Li,Xiaojie Song,Yipan Feng,Cuiting Zhang,Wei Huang
Benefiting from the extraordinary mechanical properties especially at elevated temperatures, Ni625/WC composites have been regarded as promising structural materials for deep well drilling. However, the addition and formation methods of WC would effect the mechanical properties of the composites greatly. In this work, Ni625/WC composites by spark plasma sintering technique are investigated, and the influences of WC by the external adding method and the internal in-situ formation method on the morphology, friction and fracture behaviors of the materials are analyzed systematically. It is found that the samples with externally added WC as the reinforcing phase possess enhanced wear resistance because of the high hardness and embedding depth of the externally added large-size WC. The large hardness difference with the matrix and the high brittleness lead to serious adhesive wear and poor toughness of the samples. On the contrary, the samples with in-situ WC as the reinforcing phase have superior toughness owing to the tighter bonding of in-situ generated WC to the matrix, lower brittleness of tungsten carbide and slower propagation of cracks. This work, with the systematic and comparative study of the incorporation of WC to the influence of mechanical properties of Ni625/WC, would enlighten the design of advanced metal-ceramic composites to meet the specific requirements of different structural materials.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yang Jia,Tao Li,Xiaoguang Chen,Haitao Xue,Weibing Guo,Cuixin Chen
Al 2 O 3 ceramic and 304 stainless steel were brazed with AgCuTi filler in this paper. Two kinds of composite filler were prepared by adding Cu foam and Cu foam covered with graphite (Gr-Cu foam) to relieve the residual stress of the joints. The effects of Cu foam pore size on the joints were investigated in detail, and the evolution mechanism of the joints was analyzed. Graphite-reinforced Cu foam was fabricated by spraying graphite for the first time. Results showed that the extremely low coefficient of thermal expansion of graphite and the good energy absorption performance of Cu foam were both conducive to reducing the thermal residual stress during the cooling process. Gr-Cu foam with pre-filled pores was used to solve the problems of structural dissolution of Cu foam and unfilled solder in Cu foam pores to a certain extent. And it played a key role in preventing the diffusion of metal atoms. The graphite on the surface of the Cu foam generated TiC in the brazing seam. The TiC and Cu foam promoted the formation of the TiCu strengthening phase. Furthermore, when the pore size of the Gr-Cu foam was 150 μm, the maximum shear strength of the joint was 246.84 MPa. This value was about 40% higher than that of Cu foam with the same pore size. The residual stresses of joint with and without graphite-reinforced were calculated, respectively, for both conditions. The reduction of residual stress was found after adding the graphite during brazing.
研究领域:
材料科学
·
冶金工程
·
焊接工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）