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Titanium (Ti) alloy foam was prepared by using potassium bromide (KBr) as space holder with percentage between 20 to 40 wt.%. In this work, the potential of KBr as a new space holder was determined. The Ti alloy powder and space holder were first manually mixed before being compacted using hydraulic hand press. The green compacts were then sintered at temperature of 1160°C, 1200°C and 1240°C in a tube furnace. The microstructure of the Ti alloy foams were observed by Scanning Electron Microscope (SEM). It was revealed that the porosity content in the Ti foam was in the range of 16% to 31% and density in the range of 1.5 g/cm3 to 2.6 g/cm3. Moreover, the pore size of the titanium alloy foam is in the range of 187μm to 303μm. Although the sintering temperatures were found incapable of promoting overall densification to the Ti alloy foam, 1200°C was denoted to be the maximal temperature for promoting maximal porosity to the Ti alloy foam. Nonetheless, KBr was proven to be suitable as space holder for Ti foam preparation as referred to its stability and insolubility in the Ti alloy.

The emission exhaust stack in industries must have good corrosion resistance and heat resistance in both the base metal and the welded joints. Therefore, corten steel is chosen as the base metal for the exhaust stack due to its excellent corrosion resistance and heat resistance, as well as its costeffectiveness compared to other heat-resistant steels. This study aims to analyze the welded joints of corten steel in terms of microstructure, corrosion resistance, and tensile strength using the Shielded Metal Arc Welding (SMAW) method, following the Welding Procedure Specification (WPS). The variables used in this study are the electrode variations using E7016-G and E8016-G electrodes, and the current variations of 90, 105, and 120 A. The results of this study indicate that in the metallography testing, the highest percentage of the perlitic phase is found in specimen B2, which uses the E8016-G electrode and a current of 105A, reaching 41.92% in the weld metal and 29.6% in the Heat-Affected Zone (HAZ). In the corrosion resistance testing, the corrosion rate fluctuates within the 3-hour and 6-hour time ranges, but decreases within the 10-hour time range. The lowest corrosion rate is observed in specimen B2 using the E8016-G electrode and a current of 105A. In terms of mechanical properties, the best results are obtained from the tensile testing and hardness testing of specimen B2 using the E8016-G electrode and a current of 105A.