A comparison of the Mechanical Properties and Production of Powder Metal Components made with Intralube ETM and Sintered Using Two Different Sintering Approaches.
Scot E. Coble, Penn State DuBois
Intralube Etm sees regular use in the compaction of higher density powder metal components. Although it is seeing more and more use, little work has been done to review the impact that this lubricant has on the sintering process. Here, the effect of this lubricant as a function of compact density, lubricant amount, and sintering method will be reviewed. A look at the impact on the physical properties, production rate, and quality of the final compacts will be demonstrated.
Study of Surface modification of Iron Powders That Promote Cold Sintering of Steel Compacts
Austin C Fairman, Penn State DuBois
Previously, it was shown that phosphate coated iron are excellent precursor materials to promote cold sintering and enhance strength of sintered steel compacts. In this study, we show the generic nature of cold sintering by demonstrating the phenomenon using an alternate surface modification technique that involves electroless deposition of copper or iron. The modified iron powders will be used to make steel compositions and the performance of both green compacts and sintered steel will be assessed. Mechanical properties that include tensile and transverse rupture strength measurements will be done and microstructure of the cold sintered sample will be composed against conventional PM steel of similar densities.
Metallographic characterization of liquid phase sintered PM steels using artificial intelligence
Gabrielle Laramée, Université Laval
The microstructure of admixed PM steels is generally characterized by a high level of inhomogeneity due to the existence of chemical composition gradients. The quantitative characterization of such microstructure can be quite challenging without resorting to the time-consuming task of manually identifying and delimiting a complex juxtaposition of phases. The main objective of this investigation was to assess to possibility of using an unsupervised machine learning (ML) approach to track the effect of chemical composition on the final microstructure and mechanical properties of specimens prepared following an adaptive experimental design and containing variable proportions of admixed Ni, Mn, Cu, C and pre-alloyed Mo and B. Our work showed that meaningful information can be extracted from a wide variety of microstructures and correlated to common metallurgical knowledge without the need for a human to perform the analysis of metallographic images.
Effect of grain distribution and controlled heat treatment in the micro ingot Double Press Double sintered Process towards achieving improved mechanical properties
Dakota C Stormer, Penn State DuBois
Unscreened and unannealed 100% pre-alloyed steel powder 4600V were processed under controlled conditions following recently proposed modified DPDS route. Densities of 7.3- 7.5 g/cc were achieved by pressing under different time, temperature and pressure combinations to optimize the process. Optimized samples were then analyzed for the role of microstructure and grain distribution on improvement of final density and mechanical properties. Using a micro hardness, mapping of localized hardness on large and small grain size clusters of the etched sample were conducted. Samples were then post processing using controlled heat treatments and quenching, and evaluated with XRD measurements for residual stress state on the sample surface under different compaction pressures. This was correlated with the overall densification and role of multi modal grain size and compressive surface stresses on improved mechanical properties. Mechanical characterization was done to evaluate improvements in strength by TRS testing, microhardness and improvement in fatigue life of the samples.