scholarly journals Sensitivity of direct metal laser sintering Maraging steel fatigue strength to build orientation and allowance for machining

2018 ◽  
Vol 42 (1) ◽  
pp. 374-386 ◽  
Author(s):  
Dario Croccolo ◽  
Massimiliano De Agostinis ◽  
Stefano Fini ◽  
Giorgio Olmi ◽  
Francesco Robusto ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Maraging Steel ◽  
Laser Sintering ◽  
Direct Metal Laser Sintering ◽  
Build Orientation

Wear resistance of maraging steel developed by direct metal laser sintering

2020 ◽  
Vol 10 (7) ◽  
pp. 1079-1090 ◽  
Author(s):  
Gulam Mohammed Sayeed Ahmed ◽  
Irfan Anjum Badruddin ◽  
Vineet Tirth ◽  
Ali Algahtani ◽  
Mohammed Azam Ali
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Maraging Steel ◽  
Normal Load ◽  
Testing Machine ◽  
Wear Test ◽  
Laser Sintering ◽  
Wear Testing ◽  
Direct Metal Laser Sintering ◽  
Wear Tests

This work presents wear study on maraging steel developed by additive manufacturing using Direct Metal Laser Sintering, utilizing a laser beam of high-power density for melting and fusing the metallic powders. Short aging treatment was given to the specimen prior to the wear tests. The density and the hardness of the 3D printed maraging steel were found to be better than the homogenized-aged 18Ni1900 maraging steel. The wear resistance is an important aspect that influences the functionality of the components. The wear tests in dry condition were performed on maraging steel on pin/disc standard wear testing machine. The design of experiments was planned and executed based on response surface methodology. This technique is employed to investigate three influencing and controlling constraints namely speed, load, and distance of sliding. It has been observed that sliding speed and normal load significantly affects the wear of the specimen. The statistical optimization confirms that the normal load, sliding distance, and speed are significant for reducing the wear rate. The confirmation test was conducted with a 95% confidence interval using optimal parameters for validation of wear test results. A mathematical model was developed to estimate the wear rate. The experimental results were matched with the projected values. The wear test parameters for minimum and maximum wear rate have been determined.

scholarly journals Effect of Various Peening Methods on the Fatigue Properties of Titanium Alloy Ti6Al4V Manufactured by Direct Metal Laser Sintering and Electron Beam Melting

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2216 ◽  
Author(s):  
Hitoshi Soyama ◽  
Fumio Takeo
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Fatigue Strength ◽  
Shot Peening ◽  
Electron Beam Melting ◽  
Surface Hardness ◽  
Laser Sintering ◽  
Laser Peening ◽  
Direct Metal Laser Sintering ◽  
Titanium Alloy Ti6al4v

Titanium alloy Ti6Al4V manufactured by additive manufacturing (AM) is an attractive material, but the fatigue strength of AM Ti6Al4V is remarkably weak. Thus, post-processing is very important. Shot peening can improve the fatigue strength of metallic materials, and novel peening methods, such as cavitation peening and laser peening, have been developed. In the present paper, to demonstrate an improvement of the fatigue strength of AM Ti6Al4V, Ti6Al4V manufactured by direct metal laser sintering (DMLS) and electron beam melting (EBM) was treated by cavitation peening, laser peening, and shot peening, then tested by a plane bending fatigue test. To clarify the mechanism of the improvement of the fatigue strength of AM Ti6Al4V, the surface roughness, residual stress, and surface hardness were measured, and the surfaces with and without peening were also observed using a scanning electron microscope. It was revealed that the fatigue strength at N = 107 of Ti6Al4V manufactured by DMLS was slightly better than that of Ti6Al4V manufactured by EBM, and the fatigue strength of both the DMLS and EBM specimens was improved by about two times through cavitation peening, compared with the as-built ones. An experimental formula to estimate fatigue strength from the mechanical properties of a surface was proposed.

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