ABSTRACT The current research focuses on how heating mode in powder metallurgy affects the damping properties of pure aluminum. The aluminum powder was compacted in a hydraulic press measuring 40 x 12 x 1.5mm3 and heated in a muffle furnace (conventional) and a microwave sintering furnace. The damping measurements were conducted on the samples using a dynamic mechanical analyzer under dual cantilever mode at various vibrating frequencies of 0.1, 1 and 10Hz from room temperature (RT) to 150°C at constant strain. Results demonstrated that the microwave sintered samples exhibit high storage modulus and high damping capacities compared to conventional sintered samples. The mechanisms that support this behavior are investigated and presented. Keywords: Damping; Conventional heating; microwave heating; storage modulus; sintering INTRODUCTION Powder metallurgical components have become increasingly popular in recent years for automotive and structural applications. Powder metallurgy (PM) processing has many benefits over traditional casting methods, including relatively low processing temperatures, higher final densities, near-net forming, more material use and a much more refined microstructure that offers improved mechanical properties. PM entails blending the powders, compaction at a desired pressure and eventually sintering the sample by heating it. The physical/mechanical properties of the components mostly depend on parameters like heating temperature, sintering time, heating mode and the compaction pressure. The microstructure is influenced by the sintering temperature, which plays a major role in improving the properties of composites [1-5]. Xuchao Wang et al [6] experimented with different parameters such as sintering temperature, dwell time and applied pressure to see how they affected mechanical properties. The authors were able to achieve the optimal sintering conditions, resulting in a refined grain structure with high densification. When sintered at 630°C, Baisong Guo et al [7] found that aluminum-based composites exhibit strong bonding at the interface and good densification. Similar results were obtained with sintered magnesium alloys [8]. Densification can also be improved by choosing the appropriate sintering time [9]. On the other hand, a lot of research has been done into how the heating mode in PM affects the physical/mechanical properties. Conventional, microwave and spark plasma sintering techniques are the available heating modes in PM. In traditional methods, sintering materials is done by heating compacted samples indirectly in a refractory-type electrical resistance/induction/fossil fuel furnace. To accomplish and sustain the high temperature for a long time, these furnaces use a huge number of costly heat sources, fuel and refractory materials. Microwave sintering, on the other hand, involves the materials absorbing microwave energy and converting it to heat inside their own bodies [9]. Spark plasma sintering is preferred for quick sintering and densification, particularly in the case of refractory materials. This technique enhances the properties of a material [10, 11]. Mohankumar Madhana and Gopalakrishnan Prabhakaran [12] used the PM technique to fabricate alumina/silicon carbide composites, which were then sintered at 1,500°C using both traditional and microwave methods. When comparing microwave sintering to traditional sintering, the experimental results showed that the microwave sintered samples had a higher density. Also, microwave sintering reduces crystalline size compared to traditional sintering due to the shorter sintering time. The sintering time in a microwave furnace was decreased as compared to traditional furnace heating. In general, microwave-sintered compacts have higher sintered density and bulk hardness than their conventionally sintered equivalents, despite the shorter processing time [13]. According to the findings, microwave sintering resulted in an inhomogeneous DAMPING CHARACTERISTICS OF PURE ALUMINUM: A COMPARISON OF MICROWAVE AND CONVENTIONAL SINTERING Dorathi Kare, Dept of Mechanical Engineering, Sri Vasavi Engineering College, Tadepalligudem, A.P. INDIA and Research Scholar, Dept of Mechanical Engineering, GITAM University, Visakhapatnam, 530045, INDIA; Shoba Chintada, Siva Prasad Dora, Prafulla Kumar Swain, Dept of Mechanical Engineering, GITAM University, Visakhapatnam, 530045, INDIA TECHNICAL PAPER METAL POWDER REPORT • VOL 76 NUMBER 6 • NOVEMBER/DECEMBER 2021 22