Applied Mechanics and Materials Vols. 10-12

Abstract: The equations correlated the normal load and the tip penetration depth were derived through the theoretical analysis of the penetration process of the diamond tip. Verified by experiments, the equations can reflect the penetration process of the scratching machining system and provide theoretical basis for the optimization of depth control algorithm. The control of scratching depth realized in AFM deflection mode can effectively restrain the system drift during scratching process.

Abstract: Significant aspects of intelligent maintenance include the abilities to diagnose impending failures, prognose the remaining useful lifetime of the process and schedule maintenance operations so that uptime is maximized. Prognosis is probably the most difficult of the three issues leading to total intelligent maintenance. This paper describes a fuzzy logic combined logistic regression method of fatigue severity assessment and remaining useful life prediction of gas turbine hot components. Logistic regression method is proposed to derive fuzzy logic rule base using historical maintenance running records and engineers’ experience. Implementation of the prognostic methodology presents a great opportunity to significantly enhance current engine health monitoring capabilities and risk management practices.

Abstract: According to dyeing and printing wastewater of high chroma and difficult decomposition, a new ultrasonic focalize decomposition method is provide, which can decompose those are difficult to do. In this article, Dynamic adding-pressure dissolving-air, ultrasonic focalize and flocculate floating-air are assembled to advance the treatment effect. Through the research, the dynamic models of adding pressure and dissolving air and flocculate floating-air are constructed. Based on the theory research, a experiment device is designed. The effect and influence factors are discussed, which provides a new way to process dyeing and printing wastewater of high chroma and difficult decomposition.

Abstract: This paper introduced present application in the world and some problems in the calibration technique of 3D measuring system. Auto-calibration technique of multiple targets tracking for detecting outline based on random placement and regular number is put forward. At the same time, the concrete algorithm is given. Then, according to the algorithm, the corresponding experimental result is obtained. Furthermore, the calibration accuracy is compared and analyzed. Finally, it comes to a conclusion that this algorithm can make the operation more simple and convenient. And the calibration accuracy is kept within 0.03mm.

Abstract: Based on the traditional HFCVD system, a new set of miniature HFCVD diamond film-deposition system with a swingabe substrate platform has been designed. Simulations of the substrate temperature field have been done respectively when the platform is still, rotating continuously, or swinging. The results suggest that when the swing angle is bigger than 100, uniform temperature field close to that achieved through continuous rotation can be got. So, in this paper, the crank-rocker mechanism has been used to produce a swingable substrate platform, which simplifies the traditional structure. And satisfactory temperature field can be achieved. It meets the requirements of the miniaturization design.

Abstract: Cutting tests had been done on the Austempered Ductile Iron (ADI) with ceramic cutting tools. The wear shape of the cutting tool’s surface was observed by the Scanning Electron Microscope (SEM). The micro-wear area of the tools was analyzed with energy spectrum. Study on wear shape and wear mechanisms were done when infeed cutting ADI. The result shows that: the cutting speed is an important factor to the tool wear when infeed cutting ADI with CC650 tool, and with the increase of the cutting speed, the wear value of cutting tool increases obviously. The flank of cutting tool (CC650) has wear land of definite width during cutting, and shows obvious abrasive wear. The crate wear shape of rake face is almost joined to major cutting edge, it is different from the typical crate shape of rake face. Elements Fe, Si and Mg in ADI material diffuses to the surface of cutting tools (CC650) after cutting, the diffusion exacerbates the wear of cutting tools, and the diffusion degree of rake face is larger than that of flank, abrasive wear, adhesive wear and diffusive wear is chief reasons for tools wear.

Abstract: The experiment result of base of laser cladding samples shows that more energy base absorb, more wide the Hot affect region. The base with the quenchable material will be quenched hardening and get refinement organization, such as medium steel, etc. Contrariwise the base of austenite stainless steel doesn’t have these phenomenons. Under the repeated impact load, the quenched hardening base may be softened and appear flaw easily, such as crack, etc. The base of low stiffness may be hardened in a distance.

Abstract: This article studies the two-ring-dimension-chain and the parallel connection dimension chain (simply named parallel-chain) in the machining-process-dimension-chain (MDC) and introduces their existence, and decisive position in calculating the tolerance and deviation of all kinds of process dimensions in machining process and concludes a basic idea to find a solution to them, and distribution of their tolerance and deviation. The calculating and analysis method contributes to provide a general solution to solve the dimensions in machining process. A computer aided calculating (CAC) method for the MDC in CAPP applying the MDC theory is introduced, and makes the defining and analyzing of the machining process dimension more easily, fast and practically.

Abstract: This article sets forth a new precision measurement method of CNC machine tools. The method incorporates the laser interferometer and the measurement principle of the double ball bar (DBB), and can measure the machine tool precision under the high feed rate condition. The generalized measurement model of three-axis has been built. Data analysis software is developed to simulate the run condition of machine tools. The repeatable experiment results proves that the method is feasible and its precision is higher than DBB`s.

Abstract: Ultra-precision turning tests on SiCp/2024Al and SiCp/ZL101A composites were carried out to investigate the surface quality using single point diamond tools (SPDT) and polycrystalline diamond (PCD) cutters. Examined by SEM, the machined surfaces took on many defects such as pits, voids, microcracks, grooves, protuberances, matrix tearing and so on. The results showed that surface quality debased with increasing feed rate or using of high volume fraction materials. Dry cutting would deteriorate the surface finish. It was also pointed out that SPDT outperformed PCD tools although they produced the same surface roughness Ra. Microhardness measuring showed that the deformation layer was extended to 8–16μm below the machined surface.