Design of two-dimension precision positioning mechanism for lapping arc edge diamond tool

Author(s):  
Ren Yan ◽  
Feng Chen ◽  
Xiaodan Chen ◽  
Yidan Zhou
2011 ◽  
Vol 131 (3) ◽  
pp. 275-282
Author(s):  
Kenta Seki ◽  
Hiroaki Matsuura ◽  
Makoto Iwasaki ◽  
Hiromu Hirai ◽  
Soichi Tohyama

Author(s):  
M. Ali ◽  
◽  
A. P. Kiryanov ◽  
V. I. Kovalev ◽  
V. I. Pustovoit ◽  
...  

2020 ◽  
Vol 86 (6) ◽  
pp. 62-71
Author(s):  
P. P. Sharin ◽  
S. P. Yakovleva ◽  
M. P. Akimova ◽  
V. I. Popov

The results of studying fundamental and applied problems regarding the formation of boundary layers between diamond and carbide matrix are presented with the goal to develop a highly resistant diamond tool. The new approaches to the synthesis of diamond-carbide materials combining diamond metallization and sintering in a single-stage technology are presented. The developed technology eliminates the re-heating of a metallized coatings which results in their destruction and enhanced graphitization of diamond (these phenomena restrict using metallization procedure to improve diamond retention and synthesis of high-functional composites for diamond tools). The goal of the study is analysis the structural and phase state of the «diamond – carbide matrix» interface in a diamond tool obtained by the new technology and the main factors determining the level of diamond retention in the presence of a metallized coating. Unique opportunities provided by modern high-resolution methods of research were used in the study. The elemental composition and morphological features of the diamond-matrix interface were studied using the methods of scanning electron microscopy, atomic force microscopy, X-ray microanalysis and Raman spectroscopy. Identification of the reaction products, including non-diamond carbon was performed. It is shown that the introduction of the powder-metallizer significantly modified the contact boundaries and provide conditions for improving the chemical and mechanical adhesion of the diamond-matrix system. The formation of the well-developed nano- and sub-microscale roughness of the diamond surface and dense filling of the existing voids with nanoscale layers of metal-infiltrate was revealed. The multilevel organization of highly structured elements of the transition zone with the minimal graphitization ensured the monolithic character and strength of the diamond-matrix bond. Comparative service tests of preproduction and control samples of diamond dressers proved the efficiency of developed hybrid technology (the specific performance of diamond tools increased by 39 – 45%). New fundamental and applied results have been obtained in the field of studying interface zones in crystalline multiphase systems that can be used to regulate adhesion phenomena at the interphase boundaries and develop highly efficient composite materials.


Author(s):  
Cong Wang ◽  
Yongxue Zhang ◽  
Hucan Hou ◽  
Zhiyi Yuan

Low efficiency and bad cavitation performance restrict the development of the ultra-low specific-speed centrifugal pump (ULSSCP). In this research, combined turbulent boundary layer theory with two-dimension design and two-dimension viscous hydraulic design method has been proposed to redesign a ULSSCP. Through the solution of the displacement thickness in the boundary layer, a less curved blade profile with a larger outlet angle was obtained. Then the hydraulic and cavitation performance of the reference pump and the designed pump were numerically studied. The comparison of performance of the reference pump calculated by the numerical and experimental results revealed a better agreement. Research shows that the average hydraulic efficiency and head of the designed pump improve by 2.9% and 3.3%, respectively. Besides, the designed pump has a better cavitation performance. Finally, through the internal flow analysis with entropy production diagnostic model, a 24.8% drop in head loss occurred in the designed pump.


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