By A Mystery Man Writer
The contour scan strategies in laser powder bed fusion (LPBF) of Ti-6Al-4V were studied at the coupon level. These scan strategies determined the surface qualities and subsurface residual stresses. The correlations to these properties were identified for an optimization of the LPBF processing. The surface roughness and the residual stresses in build direction were linked: combining high laser power and high scan velocities with at least two contour lines substantially reduced the surface roughness, expressed by the arithmetic mean height, from values as high as 30 µm to 13 µm, while the residual stresses rose from ~340 to about 800 MPa. At this stress level, manufactured rocket fuel injector components evidenced macroscopic cracking. A scan strategy completing the contour region at 100 W and 1050 mm/s is recommended as a compromise between residual stresses (625 MPa) and surface quality (14.2 µm). The LPBF builds were monitored with an in-line twin-photodiode-based melt pool monitoring (MPM) system, which revealed a correlation between the intensity quotient I2/I1, the surface roughness, and the residual stresses. Thus, this MPM system can provide a predictive estimate of the surface quality of the samples and resulting residual stresses in the material generated during LPBF.
The elements of French composition : John Home Cameron : Free Download, Borrow, and Streaming : Internet Archive
Food Packaging-Roles, Materials and Environmental Issues, Packaging
FREE gifts & price promise Plastics in Packaging — a Cradle to
Raw Materials: Definition, Accounting, and Direct vs. Indirect
Materials, Free Full-Text, passfeder 5mm
The United States Constitution : the full text with supplementary materials : United States : Free Download, Borrow, and Streaming : Internet Archive
Polymer, Journal
Investigation structure and properties of wire from the alloy of
Materials, Free Full-Text, super surf 1.99
Full text access through Strategian - Strategian Science