Densitometry of Powder Metallurgy Parts Using Digital Radiography

Document Type : Research Paper

Authors

1 Associate Professor,. Reactor and Nuclear Safety School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran

2 Associate Professor, Department of Physics, Imam Khomeini International University, Qazvin, Iran

3 Assistant Professor,. Reactor and Nuclear Safety School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran

4 BSc of Metallurgy Engineering, Alamut Powder Technology Company, Qazvin, Iran

5 BSc of Metallurgy Engineering, Iran nuclear regulatory authority, Tehran, Iran

Abstract

Density of manufactured specimens by powder metallurgy method is very important in determining their final quality and useful life. Existing cavities and porosity can cause changes in the density of the samples and reduce their strength. The Archimedean method is used to examine the samples’ density, in which some parts with specific dimensions of the samples are cut and their density is calculated by measuring their weight and volume. The use of non-destructive methods is preferable because of their non-destructive nature during density measurement. In this study, digital radiography testing (DRT) is proposed for this aim. The basis of DRT is X-ray attenuation in the material and it is a non-destructive test. By this technique, the density of different auto parts was evaluated by industrial digital radiography and was compared with the Archimedean method. The results show that this method has the sufficient accuracy and efficiency to measure the density of parts without damaging them. Also, using this method, the internal structure of the object and its defects can be examined.

Keywords


[1]     Selcuk C., Bond S., Woollin P., “Joining processes for powder metallurgy parts”, Powder Metall., 53 , 7–11, 2010.
[2]     German RM., “Understanding defects in powder injection moulding: causes and corrective actions”, Powder Injection Moulding Int., 6,1, 2012.
[3]     Danninger H., Weiss B., “Ultra high cycle fatigue properties of sintered steels”, Powder Metall. Progr, 1, 19–40, 2001.
[4]     Hadrboletz A., Weiss B., “Fatigue behaviour of iron based sintered material: a review”, Int. Mater. Rev. 42, 1–44, 1997.
[5]     Rahimian M., “Powder Metallurgy, a Highly Flexible Forming Method”, Powder Metallurgy & Mining,2:3, 2013, http://dx.doi.org/10.4172/2168-9806.1000e116.
[6]     GE Inspection Technologies, “Industrial Radiography Image forming techniques”, General Electric Company, )2007(, GEIT-30158 (01/07).
[7]     Bateni A., Parvin N., Ahmadi M., “Density evaluation of powder metallurgy compacts using in situ X-ray radiography”, Journal Powder Metallurgy, 57,2, 533-536, 2014, https://doi.org/10.11 79/00325899 14Z.000000000151.
[8]     Ponomarev M. G., Kappatos V., Selcuk C., Gan T.-H., Amos M., Halai H., “Digital radiographic inspection technique for production friendly quality assessment of PM parts”, Journal Powder Metallurgy, 56,2, 92-95, 2013, https://doi.org/10.1179/00325899 13Z.000000000103.
[9]     Ponomarev M. G., Selcuk C., Nicholson B., M. Iovea, et al., “Defect detection and classification system for automatic analysis of digital radiography images of PM parts”, Journal Powder Metallurgy, 57, 1, 17-20, 2014, https://doi.org/10.1179/0032589914Z.000000000151M.
[10] Sinka I.C., Burch S.F., Tweed J.H., “Measurement of density variations in tablets using Xray computed tomography”, J Pharmaceutics, 2003.
[11] M. Habibi, H. Khorsand, M. Ashtari & K. Jonghorban, “Fatigue Behavior of PM Steel ULTRAPAC-LA”, PM02 Conf., India, New Delhi, January 22-24 , 2002.
[12] Khorsand H., Habibi M., Ashtari M.& Yoozbashizadeh H., “The Role of Heat Treatment on Wear-Behavior of Powder Metallurgy Low Alloy Steels”, PM02 Conf., India, New Delhi, January 22-24, 2002.
[13] Dorobantu V., “X-rays linear attenuation coefficient in steel. I. Thickness dependence”, http://www.NDT.net, 9,12, Dec. ,2004.
[14] Dorobantu V., “Double Wall Technique pipelines' inspection using gamma rays”, http://www.NDT.net, 10, No.3, Mar. 2005.
[15] “Non-destructive testing-Qualification of radiographic film digitization systems-part 1: Definitions, qualitative measurements of image quality parameters, standard reference film and qualitative control”, EN 14096-1, European Norm. 2004.
[16] “Non-destructive testing- Qualification of radiographic film digitization systems-part 2: Minimum requirement", EN 14096-2, European Norm. 2004.