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Effects of lubrication procedure on the consolidation, sintering and microstructural features of powder compacts

Simchi, A ; Sharif University of Technology | 2003

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  1. Type of Document: Article
  2. DOI: 10.1016/S0261-3069(03)00155-9
  3. Publisher: Elsevier Ltd , 2003
  4. Abstract:
  5. The role of lubrication procedure on the consolidation behavior of metallic powders and subsequent microstructural development during sintering was investigated. Iron powder and iron-0.8 w/o graphite powder mixture were used as model materials. The effects of die wall lubrication procedure were compared to the traditional admixed powder lubrication method. The influences of manufacturing parameters such as the compacting pressure in the range of 150-800 MPa and the sintering temperature from 400 to 1300 °C were studied. It was found that the lubrication procedure has a great influence on the consolidation and microstructural features of the materials investigated. Admixed lubricant aids the densification in the low-pressure region but limits the maximum density at high pressure. On the other hand, die wall lubrication offers the possibility of achieving the required density in single pressing for parts made by conventional double pressing and double sintering route or by warm compaction technique. The method also results in the formation of more metal/metal contacts during compacting, which leads to better green strength. Moreover, during sintering at moderate temperatures the area of metallic contacts is more and stronger compared to the powder lubricated specimens. Consequently, better mechanical properties are obtained. However, after sintering at a high temperature (>1000 °C) only less total porosity of the unlubricated compacts attributes to higher performance. © 2003 Elsevier Ltd. All rights reserved
  6. Keywords:
  7. Lubrication ; Mechanical properties ; Microstructure ; Powder consolidation ; Sintering
  8. Source: Materials and Design ; Volume 24, Issue 8 , 2003 , Pages 585-594 ; 02641275 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0261306903001559