The Influence of the Roll-Laminating Process on the Bonding Quality of Polymer-Coated Steel Interface

Polymer-coated steel (PCS) is a new type of metal packaging material under development, which has better performance in saving resources, energy, and environmental protection. The lamination process has an important influence on the bonding quality of the PCS interface. PCS samples under different lamination temperatures and lamination speeds were prepared through experiments. A binding rate is defined to represent the real bonding area of the PCS interface. The micro-scratch tester and scanner are used to study the influence of the lamination process on the bonding rate and bonding strength of the PCS interface. It is proposed that the bonding rate and bonding strength of the PCS interface increases with the increase of lamination temperature and increases with the decrease of lamination speed. The PCS interface bonding rate and bonding strength are positively correlated. SEM and DSC experiments revealed the cause of bubbles on the PCS surface. It is proposed that controlling the uniformity of the TFS surface temperature can reduce the quality defects of PCS surface bubbles. Relevant research results bring guiding significance for the formation of enterprises.

The Fabrication of Polymethyl Methacrylate Nozzles for Electrohydrodynamic Printing

Electrohydrodynamic (EHD) jet printing enables rapid prototyping high-resolution and low-cost lines with width of micrometer or even nanometer. However, EHD printing always suffers from nozzle clogging when the nozzle inner-diameter decrease to micro-scale. Thus fabrication of low cost nozzles becomes significantly important. In this work, 50 μm wide and 12.5 μm deep PMMA (Polymethyl Methacrylate) nozzles were fabricated without using traditional expensive glass capillary pulling approach. To replicate PMMA nozzle with high precision, the embossing condition was optimized according to replication precision, the deformation rate, and maximum stress. To nearly fully bond PMMA nozzle with intact PMMA microchannel, the bonding condition was optimized according the bonding rate and dimension loss of PMMA microchannel. The availability of the fabricated PMMA nozzle was finally verified by EHD printing experiments.

Effect of Seawater Ageing on Fracture Toughness of Stitched Glass Fiber/Epoxy Laminates for Marine Applications

Composite materials are used in various industries such as marine, aircraft, automotive, etc. In marine applications, composites are exposed to seawater, which can affect their mechanical properties due to moisture absorption. This work focuses on the durability of composite materials under the short-term effect of seawater ageing. The specimens were prepared from glass fiber/epoxy using a hand lap-up method and stitched in the z-direction with Kevlar fiber. The specimens were submerged in seawater for 24 and 35 days. A significant decrease in maximum load was found as specimen immersion time in seawater increased. The seawater ageing also affected fracture toughness with a reduction of 30% for 24 days immersion and 55% for 35 days. The ageing also caused the swelling of composites due to moisture absorption, which increased the weight of the specimens. Compared to the dry specimens, the weight of the specimen for 24 days increases to 5.2% and 7.89% for 35 days’ seawater ageing. The analysis also showed that due to seawater ageing, the de-bonding rate increased as the number of days increased.

Investigation of Plasma Activated Si-Si Bonded Interface by Infrared Image Based on Combination of Spatial Domain and Morphology

This paper presents a detection method for characterizing the bonded interface of O2 plasma activated silicon wafer direct bonding. The images, obtained by infrared imaging system, were analyzed by the software based on spatial domain and morphology methods. The spatial domain processing methods, including median filtering and Laplace operator, were applied to achieve de-noising and contrast enhancement. With optimized parameters of sharpening operator patterns, disk size, binarization threshold, morphological parameter A and B, the void contours were clear and convenient for segmentation, and the bonding rate was accurately calculated. Furthermore, the void characteristics with different sizes and distributions were also analyzed, and the detailed statistics of the void’s number and size are given. Moreover, the orthogonal experiment was designed and analyzed, indicating that O2 flow has the greatest influence on the bonding rate in comparison with activated time and power. With the optimized process parameters of activated power of 150 W, O2 flow of 100 sccm and time of 120 s, the testing results show that the bonding rate can reach 94.51% and the bonding strength is 12.32 MPa.

Design of Ultrasonic Measurement System for BRRPO

Bonding rate of ring and piston's ontology (BRRPO) is used to describe the bonding quality of inserted ring and piston's ontology. According to the basic principle of ultrasonic flaw detection, shape of inserted ring and nature of material, penetration method is utilized to detect the bonding quality. An ultrasonic measurement system is designed. The design consists of hardware and software. Controlling process of hardware has been designed legally and made the detection precise. The design of software, based on VC++, consists of accomplishment of basic functions, such as data collection and data processed, and some special functions, such as automatic detection.

Sintering and Performance of MgO-CaO Materials with Nano-Sized ZrO2 Addition

MgO-CaO materials is one type of the refractories for substitution of MgO-Cr2O3 refractories that has been widely used in metallurgy and cement industries, but the application of MgO-CaO materials has been inhibited for its poor thermal shock resistance that is often improved by addition of ZrO2 but it results in increase of the cost. The present work investigated preparation of MgO-CaO materials by addition of nano-sized ZrO2. The results showed that the densification of the MgO-CaO refractories was promoted and the direct bonding rate of the materials was increased by addition of nano-sized ZrO2. The thermal shock resistance of the MgO-CaO refractories was appreciably improved by modification of the microstructure due to the formed fine CaZrO3 crystallines homogenously locating on the grain boundaries and triple points of the whole microstructure. The critical amount of ZrO2 addition for the purpose to improve thermal shock resistance was effective decreased.