A STUDY OF IRON POWDER COMPACTION FOR AUTOMOBILE COMPONENTS APPLICATION

Abstract

<p>The major advantage of the Powder Metallurgical (P/M) manufacturing<br />process is its ability to shape powder directly into a final component form with a<br />primary goal of a high quality, homogeneity of density and mechanical properties<br />and productivity. In this research, powder die filling, powder transfer and powder<br />compaction process have been studied in succession using a novel experimental<br />set-up that utilizes a high strength transparent wall section to observe and record<br />the particle movement and powder compaction during the entire sequence<br />leading up to the formation of a green part. The natural powder pattern itself, as<br />observed from the transparent wall section, is utilized for obtaining full-field<br />displacement and strain measurement for the first time. This strain field data is<br />converted into density distribution data and is validated through other commonly<br />used density measurement methods. The test set-up and the strain<br />measurement technique offer a means of quickly obtaining density distribution<br />data in select cases. In addition to the above, several powder flow characteristics<br />during die filling, powder transfer and powder compaction under a range of test<br />conditions have been noted through a series of high-speed photographic<br />recordings. The role of transfer speed and friction in the development of density<br />gradient and crack formation has been experimentally assessed. Another new<br />method of density measurement based on surface roughness of the compact has<br />been investigated. Finally, powder compaction simulations of the lab-based<br />experiments have been carried out using modified Drucker-Prager Cap model<br />within the ABAQUS CAE. The simulation results are in good agreement with<br />experimental data.</p>