scholarly journals On High-precision Subpixel-based Drilling Technique for Suture Needles with Thread

2014 ◽  
Vol 8 (1) ◽  
pp. 607-612
Author(s):  
Tiebo Sun ◽  
Hong Li
Keyword(s):  
Edge Detection ◽  
High Precision ◽  
Noise Suppression ◽  
Hole Drilling ◽  
Drilling Process ◽  
Structural Elements ◽  
Spatial Moments ◽  
Automated Production ◽  
Fitting Method ◽  
Drilling Method

In order to improve the automation of end-hole drilling process in the production of suture needles with thread, a high-precision subpixel-based drilling method is proposed. According to the edge detection principle in mathematical morphology, combined with the characteristics of the magnified images of the ends of suture needles to be drilled, the morphological edge detection operators with variable structural elements are constructed to achieve noise suppression and fully extract the detailed information of edges of images of needle end holes to be drilled. Then, the subdivision method of spatial moments is adopted to realize the subpixel positioning of pixel-level edges. Finally, least squares fitting method is used to achieve the high-precision positioning of center of needle end hole to be drilled. The experimental results of the 0.5 mm needle samples show that the drilling method proposed in this study has a concentricity error no more than ± 0.2 μm and an average drilling time of 0.65S. Moreover, the method also boasts good real-time performance and stability and meets the automated production needs of drilling process of suture needles with thread.

Application of EDM Hole-Drilling Method to the Measurement of Residual Stress in Tool and Carbon Steels

2006 ◽  
Vol 128 (3) ◽  
pp. 468-475 ◽  
Author(s):  
Hwa-Teng Lee ◽  
Joachim Mayer ◽  
Fu-Chuan Hsu ◽  
Werner P. Rehbach ◽  
Thomas Weirich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Tool Steel ◽  
White Layer ◽  
Cold Work ◽  
Carbon Steels ◽  
Hole Drilling ◽  
Drilling Process ◽  
Hole Drilling Method ◽  
Drilling Method

This study adopts the application of the electrodischarge machining (EDM) hole-drilling method to the measurement of residual stress in AISI D2 cold work tool steel, AISI H13 hot work tool steel, and AISI 1045 medium carbon steel. A calibration procedure based on the thermal conductivity of the material is conducted to compensate for the additional compressive stress induced in the workpiece by the EDM hole-drilling operation. Since the formation of this white layer influences the magnitude of the induced stress, the scanning electron microscopy, transmission electron microscopy, and nanoindentation techniques are used to examine the microstructure and hardness of the white layer resolidified on the EDMed surface. The experimental results reveal that combination of the hole-drilling strain-gage method (ASTM standard E837) with an EDM drilling process provides the effective means of determining the residual stress in materials with high hardness and good wear resistance.

Sequential Laser Mechanical Microdrilling of Inconel 718 Alloy

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
M. M. Okasha ◽  
P. T. Mativenga ◽  
L. Li
Keyword(s):  
Tool Life ◽  
Inconel 718 ◽  
Hole Drilling ◽  
Drilling Process ◽  
Inconel 718 Alloy ◽  
Step Process ◽  
Pilot Hole ◽  
Burr Size ◽  
New Approaches ◽  
Drilling Method

Mechanical microdrilling of nickel-based aerospace alloys suffers from premature drill breakage due to the fragile nature of the microdrill. Additionally, burr size reduction in both macro- and microscales has become one of the key problems in the drilling process. This paper presents a new method to microdrill Inconel 718 alloy using laser followed by mechanical drilling (sequential drilling). The aim of this research was to understand and evaluate the capability of using sequential laser mechanical drilling method as an effective and efficient method in drilling difficult-to-cut metals. Two new approaches were developed, namely, a two-step process of laser pilot drilling followed by twist drilling and a three-step process of laser pilot hole drilling followed by mechanical pilot drilling and then twist drilling. The holes produced by the new approaches were compared with those by mechanical microdrilling (pilot drilling and then twisting drilling). The results show that mechanical drilling eliminates the laser drilling defects. Furthermore, while large nonuniform burrs with attached cap were found in pure mechanical drilling, 75% reduction in burr size was achieved with the complimentary sequential drilling technology. Additionally, when compared with purely mechanical microdrilling, the new drilling method resulted in 240–430% tool life increase. Thus, the new drilling method presents an opportunity for industry to extend tool life and decrease burr.

STUDY OF THE DRILLING PROCESS USED IN THE HOLE-DRILLING METHOD THROUGH THRUST FORCE MEASUREMENT AND TOOL WEAR ANALYSIS

2015 ◽  
Author(s):  
Rodrigo Blödorn ◽  
Mariana Tiemi Tamura ◽  
Rodrigo Alberto Henke ◽  
Matias Roberto Viotti ◽  
Armando Albertazzi Gonçalves Jr. ◽  
...  
Keyword(s):  
Tool Wear ◽  
Thrust Force ◽  
Force Measurement ◽  
Hole Drilling ◽  
Drilling Process ◽  
Hole Drilling Method ◽  
Wear Analysis ◽  
Drilling Method

Technology and Equipment for Determination of Residual Stresses in Welded Structures Based on the Application of Electron Speckle-Interferometry

2013 ◽  
Vol 768-769 ◽  
pp. 166-173 ◽  
Author(s):  
Leonid Lobanov ◽  
Vyacheslav Pivtorak ◽  
Viktor Savitsky ◽  
Galina Tkachuk
Keyword(s):  
Residual Stresses ◽  
Turbine Rotor ◽  
Speckle Interferometry ◽  
Hole Drilling ◽  
Structural Elements ◽  
New Approach ◽  
Welded Structures ◽  
Hole Drilling Method ◽  
Drilling Method

The technology and equipment for determination of residual stresses in the welded structures, using electron speckle-interferometry combined with the hole-drilling method (ESPI-HD), have been described. A special new approach to the conventional method of speckle-interferometry to investigate the stress gradients over the test object surface has been added. The developed equipment has been applied for determination of residual stresses in the different structures: the gas-turbine rotor, the welded shell and the structural elements with the large grain size.

Measurement of Residual Stress in Diesel Engine Castings

2014 ◽  
Vol 633 ◽  
pp. 455-458
Author(s):  
Ke Liu ◽  
Cheng Zhang ◽  
Yong Kang Pu ◽  
Hua Lin Hu ◽  
Zheng An Wu
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Hole Drilling ◽  
Structural Elements ◽  
X Ray Diffraction ◽  
Hole Drilling Method ◽  
Iron Castings ◽  
Drilling Method ◽  
Service Conditions ◽  
Properties Of Materials

The mechanical properties of materials and structural components, notably fatigue life, brittle fracture, dimensional stability, deformation and crack propagation can be considerably influenced by residual stresses inside bodies. Accordingly, residual stresses analysis is a compulsory stage in the design of parts and structural elements and in the estimation of their reliability under real service conditions. In this paper, x-ray diffraction and hole-drilling method were used to measure residual stresses in diesel iron castings. The purpose is to determine the residual stresses distribution and analyze the annealing process on the influence of residual stress.

PENGEMBANGAN ALAT UKUR COMPRESSION TESTER

2019 ◽  
Vol 3 (2) ◽  
pp. 111-118
Author(s):  
Bahtiar Wilantara ◽  
Raharjo Raharjo
Keyword(s):  
Pressure Gauge ◽  
Welding Process ◽  
Field Trials ◽  
Ease Of Use ◽  
Hole Drilling ◽  
Measurement Tool ◽  
Drilling Process ◽  
Measuring Instrument ◽  
Digital Compression ◽  
Materials Used

This study aims to develop an analog compression tester measuring instrument into a digital compression tester as a measurement tool that can provide effectiveness and efficiency to users.                     This research is a research and development or R&D. This research was conducted in several steps, namely: problem identification, information gathering, product design, product manufacture, expert validation, product revision, testing, final production. The development of analog compression tester was first validated by material experts, media experts, and 15 students, and 5 students for field trials. The subjects of this study were vocational students at Taman Karya Madya Teknik Kebumen. Data collection techniques used in this study using instruments in the form of a questionnaire. The data analysis technique of this research is descriptive qualitative and quantitative descriptive percentage.                 The results of the development of digital compression tester designs are: 1) the tools and materials used are electric drill, grinding, cutter, goggles, gloves, masks, ruler, acetaminine welding, screwdriver, scissors, digital dial pressure gauge, hose, spark plugs, clamps , and nepel, 2) the manufacturing process that starts from the cutting process, the hole drilling process, the welding process and the process of connecting between components, 3) the workings of digital compression tester design that is reading the pressure or compression of the machine displayed on the monitor digitally using dial pressure digital gauge, 4) the test results obtained from the validation results from: a) material experts at 89% or Eligible; b) media experts at 85% or reasonable; c) response of field trial students in terms of ease of use and reading of 90% or feasible. Thus, the conclusion that the digital compression tester measuring instrument declared feasible to use for measurement.

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