Authors: Kazuhito Ohashi, Y. Sumimoto, Y. Fujita, Hiroyuki Hasegawa, Shinya Tsukamoto
Abstract: The grinding performance of wheel remarkably decreases by the loading of wheel surface
in dry grinding of hard carbon parts. In this report, we propose the removal method of loaded carbon
chips in which an adhesive tape is removed with carbon chips after putting on a loaded wheel surface
by an elastic roller with the setting load . The removal characteristics are experimentally investigated
by analyzing the projecting height of abrasive grains, removal force of adhesive tape and so on. The
removal method results in the enough projecting height of abrasive grain.
356
Authors: Ping Zhao, K.F. Tang, Zhi Wei Wang, Jia Jie Chen, Ju Long Yuan, X.H. He
Abstract: To evaluate the characteristics of semi-fixed abrasive plate (SAP), several parameters and relevant measurement methods are developed. The characteristic parameters include shore hardness, compression ratio, resilience ratio and shear strength. Five semi-fixed abrasive plates are manufactured with different bond concentration. The test results of five characteristic parameters of the SAP show the shore hardness, resilience ratio and shear strength increase, and compression ratio decreases with the bond concentration increasing. This test can provide instructive guides to the manufacture of SAP which can fit different occasions by changing the concentration of adhesives.
291
Authors: Bao Wen Zhang, Jian Ping Lin, Zhi Guo Lu
Abstract: In the weld-through technique of weld-bonding process, adhesive usually suffers extremely high temperature, causing damage to adhesive and consequently the joint strength. The present work studied the effect of welding parameters on the stress distribution of weld-bonded joints under tensile loading. The adhesive properties at elevated temperatures were first presented based on the experiments. Then a finite element model was developed to predict the temperature distribution of weld-bonded joint in the welding process. Effect of welding parameters on the dimensions of weld nugget and adhesive failure zone was obtained. At last, the stress distribution of weld-bonded joint under tensile loading was studied through finite element method. It has been found that both the stress near the adhesive failure zone and the maximum stress of weld nugget decrease when the welding current increases.
128
Authors: Yu Xin Li, De Yong Chen, Jun Bo Wang
Abstract: This paper presents a method of low temperature wafer level adhesive bonding using non-photosensitive bisbenzocyclobutene (BCB) from Dow Co for resonant pressure sensor package. The bonding process is performed at the temperature below 250oC, with the pressure on the wafer 2-3 Bar in vacuum in a wafer bonding system. According to the bonding process, pre-bake time, pumping time, pressure placed on the sensor and the thickness of cross-linked layer are the most important factors. Experiments show that more than 95% of the area is successfully bonded, the hermeticity maintains well after thermal shock and long term tests, and the tensile strength of the fabricated bonds is up to 40MPa. The bonding technique was successfully tested in the fabrication process of resonant pressure sensor, and the results show that this bonding technique is a viable MEMS encapsulation technology for hermetically cavity sealing.
55
Authors: Bin Cai, Ye Fa Tan, Long He, Hua Tan, Chun Hua Zhou, Qi Feng Jing
Abstract: In order to improve the anti-wear and anti-corrosion properties of mechanical parts used in high temperature friction conditions, the Ni-W alloy brush plating coatings were prepared and their tribological properties at elevated environment temperatures were investigated. The results show that the friction coefficients of Ni-W/GCr15 tribo-couples are in the range of 0.168～1.048, which take on the decreasing trend as the increase of environment temperatures. The wear losses of the coatings increase at elevated temperatures, and the critical temperature in which the coatings produce serious wear from slight wear is 250°C. The wear mechanism of the coatings are micro-cutting at room temperature, then it changes into adhesive wear accompanied by a certain of delamination when temperature is high than 250°C. When temperature is higher than 400°C, the main wear mechanism of the coatings is adhesive wear and delamination.
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