Modern Inspection Systems - Term Paper Example

Modern Inspection Systems Introduction They are several testing methods which are used in the engineering sector. They include the destructive and nondestructive testing; the latter is usually the common used method in many applications. Nondestructive testing (NDT) can be defined as a technique of analyzing that is used in industry and science to evaluate the material properties of the component or system without causing damage to them. It is a highly valued technique because it does not damage permanently the article or the component being inspected. Using this method, a lot of money and time is saved during the product evaluation, research and even troubleshooting. They are various non-destructive testing methods that are used which include magnetic-particle; ultrasonic, radiographic, eddy-current testing and liquid penetrate. NDC is a tool which is used in many areas like in mechanical engineering, forensic engineering, systems engineering, art, electrical engineering and medicine. The NDT methods rely on the use of sound, electromagnetic radiation as well as the properties of materials being used as a sample. The inside of the sample is usually examined through penetrating the radiations of electromagnetic radiation like the x-rays or even the sound waves for ultrasonic testing case. A contrast between the bulk and defect of a sample can be enhanced for visual examination with unaided eye with the use of the liquid to go through the fatigue cracks. Some methods in liquid penetrate testing use non-fluorescing or fluorescent, dyes, in fluids for those materials which are non-magnetic usually the metals. Another method is for magnetic materials that involve the use of liquid suspension of fine particles that are applied on part which is an externally applied filed of magnetism. Portable Q-810 Laser Shearography Portable Q-810 laser shearography system is a fully integrated non-integrated testing system that uses laser shearography. This system is suitable for detection of defects in large surface areas of composite materials in tough environments. Laser shearography system can detect the defects like disbands, wrinkling, crushed core, kissing bonds, impact damage among others. However, they do not need any surface preparation or even bond lines. This integrated system is optimized for inspecting very large surface areas which may include ship hulls, rocket components, aircraft fuselages, control surfaces, wings and others. The inspection rate in the full field is very rapid at the rate of 300mm by 200mm in every 10 seconds. This system is adapted to be used in all surfaces including curved and flat surfaces due to the adaptive seals at has. This system can be used independently in the local environment conditions and can be used in in-field inspections or in production. The measurement principle involves the use of highly sensitive interferometric technique which measures deformations on microscopic surfaces that is caused by internal flaws when small loads are applied on those surfaces of the objects. This is usually done using either vibration, mechanical, pressure and thermal excitation. As the material responds to the excitation, the results are displayed live and the operator interprets them. More images are processed for processing and exporting. 1 Fig. 1: Schematic diagram of the shearography system (DANTEC Dynamics. ‘Portable shearography NDT System for field use’, Journey on Product Information, vol. 2, issue 1, 2007, pp. 2-24.) Portable Q-810 laser shearography system is developed at Dantec Dynamics limited and owned by CSM Material teknik which is based in Germany. Its main activity is to develop and sale measurement systems for diagnosing and researching in the fluid mechanics, combustion technology, spray analysis and solid mechanics. Originally, a typical digital shearography camera, LTI-5100 with in-built laser, image processing computer and shearing image interferometer was being used. Aircraft radome was being tested with thermal stressed where slight temperature change of around 3-10 degrees was being applied being testing. Its speed was 5 seconds per 50cm by 75cm area. It used to display the laser rays from a distance to the object th2at was being tested. Comparing to the present system being used, the current system does not require any temperature change when testing. The current system does not also require one to place at it at a distance when testing as in the traditional system. Portable shearography system has vacuum hood with sealing’s that are flexible for attaching the machine on the component to be inspected. It has also a software package called ISTRA for analyzing the images Some of the dimensions and data involved with this portable equipment include inspection area of 300mm by 300mm. the inspection speed is at 300mm by 200 mm per 10seconds. The pressure difference is 150mbar at pressure of 50mbar of hold and 100mbar for testing. The maximum object curvature is at flat +/- 850 mm in radius with the standard seal. The vacuum hood dimensions are at 430mm in width, 280mm in diameter and 315mm in height. The length of the umbilical cable is 10m which is a standard length while the weight of the portable hood weight 7.5 kg. Fig. 2: Portable Q-810 laser shearography system inspecting a surface (DANTEC Dynamics. ‘Portable shearography NDT System for field use’, Journey on Product Information, vol. 2, issue 1, 2007, pp. 2-24.) Shearography is a cost effective and mature NDT technology for applying in the aerospace industry. Shearography provides usually provides an inspection which is rapid hence allowing immediate feedback for controlling the process and capability of the field capability. Fisher HM 2000 micro hardness tester Fisher HM 2000 micro hardness tester is flexible hardness testing equipment. Its application is usually for electroplated and paint coatings, PVD and CVD coatings, hard material diamond like carbon, synthetic and rubber hardness, surgical implants and the material analysis. Other applications for this system are found in the quality control of the coatings of the hard materials like the forming and cutting tools, on the galvanic coatings like the coatings of deposited nickel, in lacquer coatings of automotive industry, in coatings of gold contacts in the electrical components and synthetic foils. The HM 2000 micro hardness tester has a maximum load capacity of 2000mN. This helps greatly in the measurement of rough surfaces. The load resolution of this system is 0.04mN and its hardness tester’s automatic surface sensing reduces many errors of operating. The HM 2000 hardness tester uses a technique known as load/indentation depth method. This method usually measures the applied load as well as indentation depth continuously. This micro hardness tester also measures the force as indenter is removed hence providing elastic and plastic properties information of the material. The characteristics of the material like hardness as well as other characteristics of the materials including thin coatings, which may either be generated through a hardening process or deposited through galvanizing, are determined by the use of micro hardness. The HM 2000 micro hardness testing system uses load/indentation depth method also referred to as Martens Hardness HM which differentiates it from the value of conventional hardness which is determined according to the Vickers. According to this method, the indenter which is mostly Vickers or Berkovich pyramid is pressed continuously in the material being tested with a test load which is increasing. The load is then unloaded and the pyramid indentation depth of pyramid measured continuously throughout the process of penetration. The HM or the hardness value is then calculated from maximum test load that is selected as well as resultant indentation depth. Apart from trying to reduce the variability in use when determining the hardness, a very vital advantage lies in the evaluation of extremely small indentations; this is because it is not essential to measure visually the indentation. This is of great significance and of value to the applications to the rough surfaces or even course surface of the coating or the material especially where small dimension of pyramid displacement would led to measurement deviations that are unacceptable. With as high as 2000mN load capacity, the harder coatings measurements becomes even more improved. This is due to increased indentations hence reduced uncertainty in measurement. Reproducible and reliable results of testing ensure that the automated test runs. The HM 2000 micro hardness testing system is made or manufactured at the Fischer Instrument (GB) Ltd which is based in UK. Fig. 3: HM 2000 micro hardness testing system (Azom.com. ‘Fisher HM 2000 Micro Hardness Tester’, Hard testing Machines, , 2000 (accessed 3 March 2010).) The old versions of micro 3hardness testing system were not giving out precise results as the modern systems. The modern system uses software which is able to produce accurate data without the possibility of errors. The old system had load capacity of much less than 2000mN hence they had no increased indention and therefore a lot of uncertainty in the measurements. With very low load capacity, the results were less improved. The old system had no good output devices of displaying out the intended results. The current used system has good control system with a highly advanced technology of detecting even the rough surfaces compared to old a system which was not able to inspect some of the surfaces. Some of the technical data and dimensions of the HM 2000 micro hardness testing system include: maximum test load of 2000mN; maximum indentation depth of 150 micrometers; load resolution of 0.04mN; distance resolution of less than 100pm and approach speed of the indenter is less than 2 micrometers per second. The dimensions of the positioning device include a video microscope of 40 times, 200 times and 400 times magnification; manual measuring stage of 25mm by 25mm; the Measuring stage is 100mm by 100mm. Conclusion The testing systems are usually used and designed to be used to ensure the safety of the materials being used in all engineering sectors. Both systems are very effective in the testing sector to ensure that the safety of high quality is maintained. HM 2000 micro hardness testing system as a system of testing the hardness of the surfaces is very effective when used together with Portable Q-810 Laser Shearography which tests on the cracks or defects that may occur on the surfaces of the systems being used. Both systems have proved to be effective for years and a good assurance of the guaranteed safety within the engineering sector. If the hardness testing system finds that the system has some weakness, then the Portable Q-810 Laser Shearography will definitely find some defects on it when it is used. Therefore, both systems work hand in hand to ensure the safety of the systems. References Azom.com. ‘Fisher HM 2000 Micro Hardness Tester’,Hard testing Machines, , 2000 (accessed 3 March 2010). DANTEC Dynamics. ‘Portable shearography NDT System for field use’, Journey on Product Information, vol. 2, issue 1,2007, pp. 2-24. DANTEC Dynamics. ‘Portable shearography system Q-810’, Products and services, , 2008 (accessed 3 March 2010). Helmut Fisher. Path-breaking technology in the measuring microhardness and evaluating material properties’, Micro hardness Measurement, , 2007 (accessed 3 March 2010). Appendices Fig. 1: Schematic diagram of the shearography system from DANTEC Dynamics Company Fig. 2: Portable Q-810 laser shearography system inspecting a surface from DANTEC Dynamics. Fig. 3: HM 2000 micro hardness testing system manufactured by Fischer Instrument (GB) Ltd Read More