Materials
·
2024
·Vol. 17
·期 22
·5593
·
IF 3.1
Shuangqing Zhou,Stephan Handschuh-Wang,Tao Wang
The drilling of State-of-the-Art printed circuit boards (PCBs) often leads to shortened tool lifetime and low drilling accuracy due to improved strength of the PCB composites with nanofillers and higher thickness-to-hole diameter ratio. Diamond coatings have been employed to improve the tool lifetime and drilling accuracy, but the coated microdrills are brittle and suffer from coating delamination. To date, it is still difficult to deposit diamonds on ultrathin microdrills with diameters lower than 0.2 mm. To avoid tool failure, the pretreatment was optimized to afford sufficient fracture strength and enough removal of cobalt. Further, the adhesion of the diamond coating was improved by employing an interlayer comprising SiC/microcrystalline diamond, which mitigates stress accumulation at the interface. By these means, microdrills with diameters of 0.8 and 0.125 mm were coated with adherent diamonds. In this context, the composite coating with the diamond/SiC interlayer and a nanodiamond top layer featured enhanced adhesion compared to single nano- or microdiamond coatings on the WC-Co microdrills. The composite diamond-coated WC-Co microdrills featured improved wear resistance, resistance to delamination of the diamond coating, and improved performance for drilling PCBs compared to micro- and nanodiamond-coated microdrills without interlayer. In addition, a higher hole quality was achieved when the diamond-coated microdrills were used. These results signify that the composite/nanodiamond coating features the highest bonding strength and best drilling performance.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2019
·
IF 6.282
Mingqi Sun,Lei Yang,Kang Liu,Ge Gao,Zhenhua Su,Gang Gao,Benjian Liu,Weihua Wang,Jiecai Han,Bing Dai,Jiaqi Zhu
We propose a strategy to realize a vertically parallel multilayered distribution of microdiamonds in a polymeric matrix by pre-constructing layers with abundantly stacked microdiamonds. Silicone-based composites with this microdiamond arrangement exhibit interesting material properties in the through-plane direction: significant increments in thermal conductivity (335% that of composites with a random structure at a similar low loading of 24.7 vol%), and excellent dielectric properties as thermal interface materials for applications such as radars. Novel numerical models focused on this design of microdiamond arrangement are proposed to further understand mechanism of thermal conductivity increment and are found to match thermal conductivity and tendency of composites with this type of microdiamond distribution. It is revealed that adjusting microstructures in pre-constructed microdiamond layers is regarded as an effective strategy to improve further thermal conductivity of composites.
研究领域:
材料科学
·
热传导工程
·
界面材料设计
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 34
·2102108
·
IF 18.808
Yan-Wei Hu,Tai-Ping Zhang,Chun-Feng Wang,Kai-Kai Liu,Yuan Sun,Lei Li,Chao-Fan Lv,Ya-Chuan Liang,Fu-Hang Jiao,Wen-Bo Zhao,Lin Dong,Chong-Xin Shan
Optical physical unclonable functions (PUFs) have been proven to be one of the most effective anti-counterfeiting strategies. However, optical PUFs endowed with flexibility and biocompatibility have not been developed, limiting their application scenarios. Herein, biocompatible and flexible optical PUF labels are developed by randomly embedding microdiamonds in silk fibroin films. The PUF labels can be conformally attached onto the surface of complex shaped objects, providing the desired protection against fake and interior products. In this system, silk fibroin films serve as a flexible and biocompatible substrate, while the Raman signal of the microdiamonds serves as response of the excitation. The extremely high stability and random distribution of the microdiamonds ensure the performance of PUFs, and the maximum encoding capability of 2 10000 is finally realized. The cytotoxicity analysis results also verify the biosafety of the PUF system. In addition, the as-prepared PUF labels are attached onto the surface of polyethylene material, and human skin, and even have been implanted under chicken skin tissue, promising their practical applications.
研究领域:
材料科学
·
生物医学工程
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Mingqi Sun,Sai Zhang,Jing Fang,Xinru Li,WenXin Cao,XinZe Mao,Farao Zhang,Jiecai Han,Jiaqi Zhu
Polymeric composites with enhanced thermal conductivity are essential components for thermal management. Inspired by the stacked structure of adipose cells in the subcutis, we propose a strategy to construct a spatially interconnected thermal channel of microdiamonds (MDs) along vertical directions. In detail, a thermoplastic polyurethane (TPU)@MD core–shell structure was assembled via a microcladding method, which is utilized as reinforcement to fabricate the TPU@MD/poly(vinyl alcohol) (PVA) composite films through a doctor-blade coating technique. The resultant composite films exhibit a high through-plane thermal conductivity of 3.31 W/mK at a MD loading of 39 vol %, which is 195% higher than randomly dispersed composites. A two-step mathematical model was derived by the thermal resistance method to simultaneously analyze the mechanism of thermal conductivity enhancement. Meanwhile, the TPU@MD/PVA composites also reveal low dielectric loss. It is believed that this strategy to design and fabricate thermal interface materials with excellent properties provides effective guidance in thermal management applications.
研究领域:
材料科学
·
热管理工程
·
聚合物科学
·
复合材料
✓ 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）