As one of the main research fields of intelligent machining technology, monitoring and diagnosis of the cutting tool condition is of great significance to improve manufacturing efficiency and workpiece precision. Herein, the research status of intelligent monitoring of the tool condition is reviewed. The principle and method of the key technologies in intelligent monitoring system including sensor selection, feature extraction and pattern recognition are analyzed in depth. Further, the application status, existing problems and future direction of tool condition monitoring are discussed in details. The progress presented in this paper will be expected to improve the reliability and adaptability of the intelligent condition monitoring system and promote its application in the intelligent manufacturing system.

The ultra-precision manufacturing of large-size optical component is a complex system engineering that is related to the precision machine, numerical control, manufacturing technique, precision metrology and compensation, all of which depend on the development of the mechanical-electrical-control theory. In this paper, the researching progress in Department of Mechanical and Electrical Engineering of Xiamen University has been presented, which mainly focuses on the development of precision grinding machine and bonnet polishing machine together with the corresponding measuring equipment.

Because of serious abrasive flank wear of cutting tools during dry cutting of green alumina ceramics, in this paper, surface texturing with different geometrical characteristics was made on the flank face of the WC/Co carbide tools by laser. Dry cutting tests on the green alumina ceramics were carried out with these flank-face textured tools and a conventional WC/Co carbide tool, the wear resistance of these flank-face textured tools was investigated. Results show that there is only mild wear on the rake face, while flank face reveals serious abrasive wear. The flank wear of the flank-face textured tools is significantly reduced compared with that of the conventional one, and the flank-face textured tools with micro-scale grooves on the flank face parallel to the main cutting edge (AT-1) have the most improved flank wear resistance. Mechanism responsible are found that the textures on the flank face exhibited derivative-cutting phenomenon during dry cutting of green alumina ceramics, which serve as the removal of hard inclusion between the tool-workpiece interface. The derivative-cutting is found to be beneficial to the decrease of the flank wear of the flank-face textured tools. The textures on the flank faces can also be acted as storage for powder chip which can protect the texture groove from abrasion.

With the application of precision hirth couplings indexing table in precison mechanical machining field,the needs for large load capacity is proposed. Based on the analysis of the structure of the hirth-coupling indexing table, the FEA and design and experiments are carried out on the parameters of hirth sharp, locking force and meshing state of the hirth. A new kind of gear lapping process is proposed, which improves the precision and efficiency of the hirth lapping, and finally guarantees the precision of the high load hirth couplings indexing table.

To make a further understanding of the materials removal mechanisms of polycrystalline sintered silicon carbide (SiC) ceramics, a single diamond grain scratch platform was built to carry a single diamond grain scratch test on the polycrystalline solid phase sintered silicon carbide ceramics. In the scratching process, the chip formations were observed and the scratching force signals were collected and analyzed, then the scratch morphologies were observed with an optical microscope.The results show that the chip forms of sintered SiC ceramics are classified into continuous chips and collapsing chips,and scratching process has in turn experienced continuous chips formation stage, continuous chips accumulation stage and chips collapsing stage. Besides, when the scratching speed v=0.01mm/s, there is a significant turning point of tangential and normal scratch force at the time of 16s. Whereas, at the scratching speed of 0.04mm/s, the turning point just appears in normal scratching force, and the normal grinding force fluctuates heavily when the scratching time exceeds 12.5s, which may be due to the collapsing chips formation. What’s more, even the SiC ceramic materials are removed in ductile mode, there are fishscales cracks appearing on the scratching surface. When polycrystalline SiC ceramics removed in brittle mode, the fractured surfaces transforms from the discontinuous region into the continuous region with the increasing scratching depth. Eventually,the fractured surface extends to the non-scratching area.

During the femtosecond laser processing, how to break through the diffraction limit has always been an important problem. In recent years, nanospheres auxiliary femtosecond laser near field processing with characteristic size beyond the diffraction limit is recognized and developed gradually. It can fabricate nanoholes on the substrate surface of which scale is smaller than the incident laser diffraction limit, and can realize large area processing. In this paper, we will focus on the metal nanospheres and dielectric nanospheres, and introduce the study of nanospheres assisted femtosecond laser near field processing.

Stack materials composed of CFRP (Carbon Fiber Reinforced Plastic) and titanium alloys are widely used in the aerospace field due to their excellent properties. However, the machining properties of the two materials are quite different in all aspects. During the single-shot drilling of compound stacks, some defects like entrance spalling and hole wall scratching are easily induced by the evacuation of titanium alloy chips. In order to improve the hole quality of stack materials, this research studied the influence of different amplitudes (A=0μm, 20μm, 40μm, 60μm) on cutting force, cutting temperature and hole quality by comparing the low frequency vibration drilling with the traditional drilling. The results show that the average axial force decreases with the increase of amplitude while the maximum axial force increases. Lowfrequency vibration drilling drills the temperature to drop somewhat compared to the traditional drilling. Vibration drilling has no improvement on decreasing delamination defects and it tends to increase defects, but it can improves the quality of CFRP hole walls.

TC4 titanium alloy was cut in high-speed under dry and minimal quantity lubrication (MQL) conditions, with TiAlN-F, AlTiN-ML and (nc-AlTiN)/(a-Si3N4) carbide coating tools. Tools life were compared, tools wear and failure modes were analysed, tool wear mechanisms were studied. The results showed that different coatings had little effect on tool life under dry cutting condition. Under the MQL（Minimal Quantity Lubrication） condition, the coating could significantly reduce tool wear and improve tool life, and (nc-AlTiN)/(a-Si3N4) coating has the best performance. In high-speed cutting of TC4 titanium alloy, wear mechanism was more complex, due to the interaction of various tool wear patterns. Adhesive wear, oxidative wear, diffusion wear, abrasive wear were main tool wear, chipping and coating spalling were main failure modes.

To solve the problems arising in the onsite management for digital assembly of civil aircraft in our country, such as the conservative onsite management measures and messy production data management, the technologies of digital assembly line are reviewed, leading to the application of RFID in this field, which fulfills the digitalization and intellectualization of the onsite management. Using IDEF0 to establish civil aircraft digital assembly scene management model and have a variety of detailed information which the flow of business information; and then use the idea of object-oriented analysis and design of production management system, using B/S structure and combined with PDM technology and the system architecture is given; finally, introduces the system platform which is development required, the technology of environment and database, using ERP thought to build system model , and showed the example interface of system.

During the milling process of 6061 aluminum alloy, the tool is seriously worn and the machining efficiency is low, manufacturing quality is poor due to the severe thermal mechanical coupling of the cutting tools. The wear morphology of the tool was observed and analyzed by the VH-Z20W observing system and energy spectrum analysis (EDS). During the cutting process, the machined topography of the workpiece was observed, and the change of the workpiece shape with the tool wear is analyzed. The results show that when milling 6061 aluminum alloy with uncoated carbide tools, tiny chipping of the cutting tool is easy to occur at the beginning of milling. During the milling process, the diffusion has greater impact on the tool wear. In the early wear of the tool, the surface roughness of the workpiece is increased obviously, and the surface roughness of the workpiece is increased slowly when the wear amount increases uniformly.

The friction flow spot welding experiment has been performed on 1mm thick aluminum alloy 6061-T6.The process, microstructure and properties of welded joints were analyzed. The results show that the welded joints can be divided into four regions namely weld nugget zone, thermo-mechanical affected zone, heat affected zone and base material zone. The weld nugget zone has the tiniest grains. Down force, welding rotational speed and welding time have influences on the properties of the welded joints. In this paper, the author selects down force as the parameter for controlling the plunge depth of the tool. When down force ≤ 2300N, the hooking defeat hasn't inserted into the top surface of the upper sheet, the fracture mode acts as the “shear fracture”. When down force > 2300N, the fracture mode acts as the “plug fracture”.The study shows that when choosing down force 2300N, welding rotational speed 2000r/min, welding time 10s as the welding parameter, good weld joints of 1mm thick aluminum alloy 6061-T6 can be got.

This paper introduces the digital adaptive processing line of precision forging blades of a certain type of engine, analyzes the quality control points of the digital adaptive machining process, and studies the support and operation process quality control of the digital adaptive precision forging vane processing line, and puts forward the complete quality control requirement.

Structure evolution of the drawing state CP (Commercially Pure) titanium is studied under different heating temperature, the recrystallization temperature is determined. The results show that the tensile strength of rivets set materials drawing state CP Ti is higher than 720MPa. In the condition of 20min heat preservation, reply temperature of CP Ti is from 550- 600 ℃ , and the recrystallization temperature is from 600-650 ℃ . And the recrystallization is completed when the temperature reaches 650℃ in which the strength of extension is 525MPa. Grains become equal shape, which size is 2-5μm.The recrystallization performance of drawing state CP Ti is affected by the heat preservation time. When there is no heat preservation, recrystallization would not fully complete on the temperature of 650℃ in the material. When the time of heat preservation is 20 min, fully recrystallization will take place successfully in the materials and its organization will be in good condition. When the heat preservation temperature reaches 1h at 650℃ , material organization will become bulky and its plastic performance will degrade. There are more effect on grain size than microhardness, the grain size is small when cooling in water under heating temperature 600-650℃ .