• Title/Summary/Keyword: Instrumented indentation technique

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Hardness Estimation of Compressor Journal for a Use of Instrumented Indentation Techniques (계장화 압입시험법을 이용한 차량용 컴프레서 저널 경도 평가)

  • Kwak, Sung-Jong;Jin, Ji-Won;Kim, Tae-Seong;Noh, Ki-Han;Kang, Ki-Weon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.376-381
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    • 2012
  • This paper deals with application of instrumented indentation technique for quality inspection methodology for automobile component. For this, the instrumented indentation tests were performed the normal and cracked compressor journal, which is made from spheroidal graphite cast iron and utilized in air-conditioning system. And the Brinell hardness was estimated using the unloading slope and maximum indentation force. With the aid of Normal distribution, this Brinell hardness was statistically compared and analyzed with hardness measured by indentation hardness tests. Also, application possibility of reliability-based quality inspection criteria for compressor journal was evaluated through the probabilistic analysis for the Brinell hardness estimated by instrumented indentation technique.

Characterization of Elastic Modulus and Work of Adhesion in Elastomeric Polymer through Micro Instrumented Indentation Technique (마이크로 압입시험기법의 응용을 통한 탄성체 고분자 소재의 역학적 특성화 및 계면 접합에너지 평가기법 연구)

  • Lee, Gyu-Jei;Kang, Seung-Kyun;Kang, In-Geun;Kwon, Dong-Il
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1744-1748
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    • 2007
  • In this study, the Johnson-Kendall-Roberts (JKR) theory was combined with the instrumented indentation technique (IIT) to evaluate work of adhesion and modulus of elastomeric polymer. Indentation test was used to obtain the load-displacement data for contacts between Tungsten Carbide indenter and elastomeric polymer. And the JKR contact model, contrived to take viscoelastic effects of polymer into account, was applied to compensate the contact area and the elastic modulus which Hertzian contact model would underestimate and overestimate, respectively. Besides, we could obtain the thermodynamic work of adhesion by considering the surface energy in this contact model. In order to define the relation between JKR contact area and applied load without optical measuring of contact area, we used the relation between applied load and contact stiffness by examining the correlation between JKR contact area and stiffness through dimensional analysis with 14 kinds of elastomeric polymer. From this work, it could be demonstrated that the interfacial work of adhesion and elastic modulus of compliant polymer can be obtained from a simple instrumented indentation testing without area measurement, and provided as the main algorithm of compliant polymer characterization.

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Mechanical Characterization of Elastomeric Polymer Through Micro Instrumented Indentation Technique (마이크로 압입시험기법의 응용을 통한 탄성체 고분자 소재의 역학적 특성화 및 계면 접합에너지 평가기법 연구)

  • Lee, Gyu-Jei;Kang, Seung-Kyun;Kang, In-Geun;Kwon, Dong-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.9
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    • pp.951-959
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    • 2007
  • In this study, the Johnson-Kendall-Roberts(JKR) theory was combined with the instrumented indentation technique (IIT) to evaluate work of adhesion and modulus of elastomeric polymer. Indentation test was used to obtain the load-displacement data for contacts between Tungsten Carbide indenter and elastomeric polymer. And the JKR contact model, contrived to take viscoelastic effects of polymer into account, was applied to compensate the contact area and the elastic modulus which Hertzian contact model would underestimate and overestimate, respectively. Besides, we could obtain the thermodynamic work of adhesion by considering the surface energy in this contact model. In order to define the relation between JKR contact area and applied load without optical measuring of contact area, we used the relation between applied load and contact stiffness by examining the correlation between JKR contact area and stiffness through dimensional analysis with 14 kinds of elastomeric polymer. From this work, it could be demonstrated that the interfacial work of adhesion and elastic modulus of compliant polymer can be obtained from a simple instrumented indentation testing without area measurement, and provided as the main algorithm of compliant polymer characterization.

Hardness Evaluation of Spot Welding Using Instrumented Indentation Technique (계장화 압입시험법을 이용한 점용접부의 경도평가)

  • Jin, Ji-Won;Kwak, Sung-Jong;Yoo, Dong-Ok;Kim, Tae-Seong;Kang, Ki-Weon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.9
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    • pp.1081-1086
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    • 2012
  • This study deals with hardness evaluation for spot welding by using an instrumented indentation technique to improve the quality of the inspection methodology. First, an instrumented indentation test and a Rockwell hardness test were performed for normal and abnormal spot welding. The hardness to indentation force-displacement curve obtained using each of the tests was compared. Furthermore, an analysis was conducted using the hardness obtained by the instrumented indentation technique. A quality control standard based on reliability was this evaluated for spot welding.

High-temperature Mechanical Properties Measurement and Life Assessment of Boiler Equipment by Instrumented Indentation Technique (계장화 압입시험법을 이용한 보일러 설비의 고온 기계적 물성 측정과 수명 평가)

  • Ro, Dong-Seong;Hong, Jeong-Wha;Kim, Kwang-Ho;Lee, Jung-Jun
    • Journal of the Korean Society of Safety
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    • v.24 no.3
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    • pp.1-6
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    • 2009
  • Recently power plants and oil refineries are focusing on capacity enlargement for better efficiency through higher temperature and higher pressure. Thickness of boiler tubes becomes lessened due to oxidation and erasion caused by high temperature bums gas flowing over tubes outside. Accordingly, mechanical stress of tubes is increasing and that is a critical factor to make a crack and fracture. To prevent those sorts of accidents, aging assessment for proper periodic repair and replacement should be conducted reliably and reasonably. We performed IIT test on Cr-Mo steel, one of the most heat-resistant materials for facilities in power plants, and we report the test result and the considerable effectiveness of IIT test.

Measurement of Weld Material Properties of Alloy 617 Using an Instrumented Indentation Technique (계장화 압입시험법에 의한 Alloy 617 용접 물성치 측정)

  • Song, Kee-Nam;Hong, Sung-Deok;Ro, Dong-Seong;Lee, Joo-Ha;Hong, Jung-Hwa
    • Journal of Welding and Joining
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    • v.31 no.5
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    • pp.41-46
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    • 2013
  • Different microstructures in the weld zone of a metal structure such as a fusion zone or heat affected zone are formed as compared to the parent material. Thus, the mechanical properties in the weld zone are different from those in the parent material. As the basic data for reliably understanding the structural characteristics of a welded PCHE specimen to be made of Alloy 617, the mechanical properties in the weld zone and parent material for a Alloy 617 plate are measured using an instrumented indentation technique in this study.

Measurement of Weld Mechanical Properties of SUS316L Plate Using an Instrumented Indentation Technique (계장화 압입시험법에 의한 SUS316L판의 용접부 기계적 물성치 측정)

  • Song, Kee-Nam;Hong, Sung-Deok;Ro, Dong-Seong
    • Journal of Welding and Joining
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    • v.31 no.2
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    • pp.37-42
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    • 2013
  • Different microstructures in the weld zone of a metal structure such as a fusion zone or heat affected zone are formed as compared to the parent material. Thus, the mechanical properties in the weld zone are different from those in the parent material. As the basic data for reliably understanding the structural characteristics of welded PCHE prototype made of SUS316L, the mechanical properties in the weld zone and parent material for a SUS316L plate are measured using an the instrumented indentation technique in this study.

Evaluation of Mechanical Properties by Using Instrumented Indentation Testing for Resistance Spot Welds (비파괴 계장화 압입시험을 이용한 저항 점용접부 물성 평가)

  • Choi, Chul-Young;Kim, Jun-Ki;Hong, Jae-Keun;Yeom, Jong-Taek;Park, Yeong-Do
    • Journal of Powder Materials
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    • v.18 no.1
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    • pp.64-72
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    • 2011
  • Nondestructive instrumented indentation test is the method to evaluate the mechanical properties by analyzing load - displacement curve when forming indentation on the surface of the specimen within hundreds of micro-indentation depth. Resistance spot welded samples are known to difficult to measure the local mechanical properties due to the combination of microstructural changes with heat input. Particularly, more difficulties arise to evaluate local mechanical properties of resistance spot welds because of having narrow HAZ, as well as dramatic changed in microstructure and hardness properties across the welds. In this study, evaluation of the local mechanical properties of resistance spot welds was carried out using the characterization of Instrumented Indentation testing. Resistance spot welding were performed for 590MPa DP (Dual Phase) steels and 780MPa TRIP (Transformation Induced Plasticity) steels following ISO 18278-2 condition. Mechanical properties of base metal using tensile test and Instrumented Indentation test showed similar results. Also it is possible to measure local mechanical properties of the center of fusion zone, edge of fusion zone, HAZ and base metal regions by using instrumented indentation test. Therefore, measurement of local mechanical properties using instrumented indentation test is efficient, reliable and relatively simple technique to evaluate the tensile strength, yield strength and hardening exponent.

Evaluation of Residual Stress on Welded Joint in API X65 Pipe Line through Nondestructive Instrumented Indentation Technique (비파괴 계장화 압입시험기법을 통한 API X65 배관 용접부 잔류응력 평가)

  • 지원재;이윤희;김우식;김철만;권동일
    • Journal of Welding and Joining
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    • v.21 no.5
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    • pp.547-554
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    • 2003
  • Apparent mechanical properties in structural components can be different from the initially designed values due to the formation of the residual stress in metal forming and welding. Therefore, the evaluation of residual stress has great importance in the reliability diagnosis of structural components. A nondestructive instrumented indentation technique has been proposed to evaluate various strength concerning mechanical properties from the analysis of load-depth curve. In this study, quantitative residual stress estimation on API X65 welded joints for natural gas pipeline was performed by analyzing the variation of indentation loading curve by residual stress through a new proposed theoretical model. The residual stress from the indentation method was compared with that from the saw-cutting method.

The Strength Evaluation of Wheel for Railway Rolling Stock Using Instrumented Indentation Test (계장화 압입시험을 이용한 차륜의 강도평가)

  • Kim, Chul-Su;Ahn, Seung-Ho;Chung, Kwang-Woo;Park, Shin-Ho;Kang, Gil-Hyun
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1607-1612
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    • 2007
  • To assure safe usage of railway rolling stock, it is important to evaluate the strength of the wheel which is core part in bogies. However, conventional standard testing methods using destructive technique could not evaluate mechanical properties of degraded wheels during rolling stock maintenance work. Instrumented indentation test is a new way to evaluate nondestructively the strength of mechanical components by analyzing indentation load-depth curves. In this study, to evaluate tensile strength of the wheel, instrumented indentation test is performed nondestructively according to KS B 0950. Furthermore, test results are examined by tensile test in accordance with KS R 9221.

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