Xie Huimin

Electron moiré method and its application to micro-deformation measurement

In this paper, the single and two deposited metal layers method were proposed to produce the model grating for electron moire method. The measurement principle of electron moire method and the techniques for manufacturing model grid are expounded in detail. The accuracy of measuring strain using this method is discussed. The gratings with single deposited layer and two deposited layers with high frequency up to 5000 lines/mm were produced on different substrates. From the experimental results, both single deposited metal layer and two deposited metal layers gratings showed their heat resistance ability. Using the gratings produced and a replicated model grid, the electron moire method was applied to measure the deformation of the strain around holes in a polyimide resin substrate, thermal strain of electronic packaging component and tensile creep around grain boundary in a pure copper specimen.

The dynamic deformation measurement of the high speed heated LY12 aluminium plate with moire interferometry

Abstract Using the moire interferometry method, the dynamic deformation of a pre-loaded LY12 aluminium tensile specimen under a thermal heating was studied. The dynamic deformation of the specimen under high speed heating procedures was recorded with a film video camera. The experimental results showed that it is feasible to use moire interferometry for measuring dynamic deformations under conditions of fast heating.

Thermal deformation measurement of electronic package using advanced moire methods

In this paper, the laser moire interferometry method, the electron beam moire method, the atomic force microscope (AFM) scanning moire method, and the scanning electronic microscope (SEM) scanning moire method are used to measure the thermal deformation of electronic packages. The measurement principle and the adaptability of these methods are discussed and compared. 1200 lines/mm holographic gratings in ultra low expansion (ULE) mold plates were replicated on the cross section of the measured sections in a ball grid array (BGA) electronic package and a quad flat package (QFP). These holographic gratings were fabricated on ULE mold plates and were replicated on the measured area at 100/spl deg/C and 150/spl deg/C, respectively. The deformation measurement principles and experimental techniques using these moire methods are described. As an application, the deformation in the different solder joints in the BGA electronic package and in the area near the die corner of the QFP electronic package was measured using these methods. Some useful results were obtained.

600°C creep analysis of metals using the Moiré interferometry method

Abstract Using a holographic grating for the high temperature and Moire interferometry method, this paper offers an experimental study on the residual creep strain of a No. 20 carbon steel specimen with a central hole under a tensile load. The test was carried out at 600°C for 40 h. The residual creep strain distribution of the specimen over the minimum cross-section and the changing trend of the strain-concentration factors with creep were obtained.

Archimedes Spiral Cracks Developed in a Nanofilm/Substrate System

Perfect Archimedes spiral cracks at micrometer scales are found in a colloid film of several hundred nanometers in thickness coated on a glass substrate. To explain the formation of this kind of spiral crack, the relation between the geometrical properties of the Archimedes spiral and the growth kinematics of the spiral cracks are analyzed. Meanwhile, the initiation and propagation of the spiral cracks are speculated upon logically from the specific material system based on sufficient evidence. In addition, we introduce a new cracking phenomenon and provide an insight into the new mechanism for crack propagation in soft material nano films coated on stiff substrates.

Deformation Measurement of Impulsed Viscoelastic Plate with Moire Method

The dynamic deformations of impulsed viscoelastic plates measured with the moire method are discussed. A new method for producing visco-photoelastic material is proposed. The material was processed as plate type specimens with elliptical or circular holes, and utilized to investigate its dynamic deformation behavior at 42°C. The measuring method and procedures, as well as the experimental results are discussed in detail.

A study on the creep deformation of high temperature pipeline using the Moiré method

In this paper, an experimental study on the long-term creep deformation of 475°C pipeline was conducted using the Moire method. The experimental principle and procedure, as well as the accuracy of measurement, were discussed in detail. The successful result verifies long-term measurement of the creep of pipeline using the Moire method is feasible.

Experimental study on the damage progression of an aluminium plate irradiated by CO2 laser

Abstract In this paper, the damage progression of a loaded aluminium plate irradiated by CO2 laser was analysed using grid method and the micrography technique. The residual deformations near the illuminated area at different irradiation times were obtained. Using the micrography technique, the propagation process of the minute crack was recorded. Furthermore, the residual stength of the specimen after illumination was investigated. The experimental results are discussed in detail.