Impact Energy Absorbing System for Space Lander Using Hemispherical Open-Cell Porous Aluminum

2018 ◽  
Vol 933 ◽  
pp. 337-341 ◽  
Author(s):  
Koichi Kitazono ◽  
Raita Tada ◽  
Yoshikazu Sugiyama ◽  
Toko Miura

Impact energy absorbing system for space lander is an important technology for space exploring missions. Open-cell porous aluminum manufactured through 3D selective laser melting process has been used on the energy absorbing system. Compression tests for cylindrical and hemispherical shaped porous aluminum with different porosities revealed the high potential as an energy absorbing component. It was found that the suitable heat treatment were effective to increase the energy absorbing potential of the porous aluminum.

2017 ◽  
Vol 62 (2) ◽  
pp. 1341-1346 ◽  
Author(s):  
K.-A. Lee ◽  
Y.-K. Kim ◽  
J.-H. Yu ◽  
S.-H. Park ◽  
M.-C. Kim

AbstractThis study manufactured Ti-6Al-4V alloy using one of the powder bed fusion 3D-printing processes, selective laser melting, and investigated the effect of heat treatment (650°C/3hrs) on microstructure and impact toughness of the material. Initial microstructural observation identified prior-βgrain along the building direction before and after heat treatment. In addition, the material formed a fully martensite structure before heat treatment, and after heat treatment,αandβphase were formed simultaneously. Charpy impact tests were conducted. The average impact energy measured as 6.0 J before heat treatment, and after heat treatment, the average impact energy increased by approximately 20% to 7.3 J. Fracture surface observation after the impact test showed that both alloys had brittle characteristics on macro levels, but showed ductile fracture characteristics and dimples at micro levels.


2018 ◽  
Vol 941 ◽  
pp. 698-703 ◽  
Author(s):  
Milad Ghayoor ◽  
Sunil B. Badwe ◽  
Harish Irrinki ◽  
Sundar V. Atre ◽  
Somayeh Pasebani

Water atomized and gas atomized 17-4 PH stainless steel powder were used as feedstock in selective laser melting process. Gas atomized powder revealed single martensitic phase after printing and heat treatment. As-printed water atomized powder contained dual martensitic and austenitic phase. The H900 heat treatment cycle was not effective in enhancing mechanical properties of the water atomized powder after laser melting. However, after solutionizing at 1315 oC and aging at 482oC fully martensitic structure was observed with yield strength of 1000 MPa and ultimate tensile strength of 1261 MPa which are comparable to those of gas atomized, 1254 MPa and 1300 MPa, respectively. Improved mechanical properties in water atomized powder was found to be related to presence of finer martensite. Our results imply that water atomized powder is a promising cheaper feedstock alternative to gas atomized powder.


2019 ◽  
Vol 822 ◽  
pp. 549-555
Author(s):  
Igor A. Polozov ◽  
Evgenii Borisov ◽  
Vera Popovich

This work investigates the Selective Laser Melting (SLM) process for the in-situ synthesis of Ti-5Al and Ti-6Al-4V alloys using elemental powder mixture. Elemental spherical powders were used to prepare a powder mixture and then samples were produced by SLM using different volume energy density. The effects of volume energy density during SLM on samples’ relative density, chemical composition, microstructure and microhardness before and after heat treatment have been studied. It was shown that volume energy density during the SLM process significantly effects the density, microstructure of Ti-5Al and Ti-6Al-4V alloys, as well as, the microhardness of Ti-6Al-4V obtained from elemental powders.


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