Direct Metal Laser Sintering of Maraging Steel: Effect of Building Orientation on Surface Roughness and Microhardness

2018 ◽  
Vol 5 (9) ◽  
pp. 20485-20491 ◽  
Author(s):  
Tarun Bhardwaj ◽  
Mukul Shukla
Keyword(s):  
Surface Roughness ◽  
Maraging Steel ◽  
Laser Sintering ◽  
Direct Metal Laser Sintering ◽  
Building Orientation

Rapid Manufacturing with Direct Metal Laser Sintering

2002 ◽  
Vol 758 ◽  
Author(s):  
J-E. Lind ◽  
J. Hanninen ◽  
J. Kotila ◽  
O. Nyrhila ◽  
T. Syvanen
Keyword(s):  
Surface Roughness ◽  
Layer Thickness ◽  
Process Development ◽  
Die Casting ◽  
Laser Sintering ◽  
Thin Layers ◽  
Rapid Manufacturing ◽  
Manufacturing Processes ◽  
Direct Metal Laser Sintering ◽  
Process Work

ABSTRACTThe term Rapid Manufacturing is today very often used as a substitute for Rapid Prototyping, because the manufacturing processes and materials have developed so much that the parts produced with the machines can even be used as functional production parts. For Direct Metal Laser Sintering (DMLS) this was enabled by the introduction of the powders for 20 micron layer thickness; steel-based powder in 2001 and bronze-based powder in 2002. Successful rapid manufacturing with DMLS does not only mean the reduction of layer thickness, but it is a sum of many factors that had to be optimized in order to make the process work with the 20 micron layer thickness: the metal powder behavior in very thin layers is not the same as with thicker layers, the demands for the support structures are higher and the possibility of using multiples of the layer thickness gives additional freedom. By optimizing the process parameters the UTS values for the steel-based powder increased up to 600 MPa and for the bronze-based powder up to 400 MPa. At the same time the surface roughness (Ra) values after shot peening were 3 microns and 2 microns, respectively. Although using thinner layers also increases the building time the advantage is gained in drastically reduced finishing times due to increased surface quality and detail resolution. Typical geometries produced by DMLS are difficult-to-manufacture components and components typically produced by P/M or even by die-casting. The paper covers the development aspects in both material and process development and also presents some realized case studies.

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.

Mass Finishing of Parts Produced by Direct Metal Laser Sintering

Volume 3 ◽  
2004 ◽  
Author(s):  
A. Boschetto ◽  
F. Veniali ◽  
F. Miani
Keyword(s):  
Surface Roughness ◽  
Industrial Process ◽  
Mechanical Action ◽  
Laser Sintering ◽  
Main Process ◽  
Direct Metal Laser Sintering ◽  
Complicated Shape ◽  
Mass Finishing ◽  
Barrel Finishing ◽  
Established Technique

This paper presents some practical considerations on finishing of parts made by direct metal laser sintering (DMLS). The main process capabilities limitations of this promising rapid tooling technique are in fact in the surface roughness of the produced parts. This fact hinders the introduction of DMLS as a widely employed industrial process, especially for what concerns the production of moulds and inserts and allows their use only as preseries tools in injection moulding of plastics, since the requirements for preseries tools are worse than those needed during the process. Barrel finishing, in turn, is a well established technique to improve the roughness of parts of complicated shape by means of a soft mechanical action over the surface. The results herewith presented show that it is possible to achieve roughness of the order of 1 μm Ra even when starting from initial roughness of the order of 15 μm Ra, i.e. those typically attained by DMLS.

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

scholarly journals An Analysis of the Surface Geometric Structure and Geometric Accuracy of Cylindrical Gear Teeth Manufactured with the Direct Metal Laser Sintering (DMLS) Method

2019 ◽  
Author(s):  
Jadwiga Małgorzata Pisula ◽  
Grzegorz Budzik ◽  
Łukasz Przeszłowski
Keyword(s):  
Surface Roughness ◽  
Geometric Structure ◽  
Gear Tooth ◽  
Spur Gear ◽  
Laser Sintering ◽  
Tooth Surface ◽  
Direct Metal Laser Sintering ◽  
Cylindrical Gear ◽  
Sand Blasting ◽  
Gear Teeth

This paper presents findings concerning the accuracy of the geometry of cylindrical spur gear teeth manufactured with the direct metal laser sintering (DMLS) method. In addition, the results of the evaluation of the tooth surface geometric structure are presented in the form of selected two-dimensional and three-dimensional surface roughness parameters. An analysis of the accuracy of the fabricated gear teeth was performed after gear sand-blasting and gear tooth milling processes. Surface roughness was measured before and after sand-blasting and gear tooth milling. The test gear wheel was manufactured from GP1 high-chromium stainless steel on an EOS M270 machine.

Surface roughness and densification correlation for direct metal laser sintering

2020 ◽  
Vol 107 (5-6) ◽  
pp. 2833-2842 ◽  
Author(s):  
Faridreza Attarzadeh ◽  
Behzad Fotovvati ◽  
Michael Fitzmire ◽  
Ebrahim Asadi
Keyword(s):  
Surface Roughness ◽  
Laser Sintering ◽  
Direct Metal Laser Sintering

Study of Condensate Generated During Direct Metal Laser Sintering

2017 ◽  
Author(s):  
Jagadish Chandra Achinadka
Keyword(s):  
Maraging Steel ◽  
Laser Sintering ◽  
Steel Grade ◽  
Process Efficiency ◽  
Layer By Layer ◽  
Direct Metal Laser Sintering ◽  
Additive Manufacturing Technology ◽  
High Intensity Laser ◽  
Xrd Studies ◽  
Intensity Laser

DMLS (Direct Metal Laser Sintering), an additive manufacturing technology, is increasingly becoming popular to build intricate high quality functional parts & rapid prototypes. DMLS technology uses a high intensity laser to build components layer by layer, directly from metal powder. CAD data is directly converted to part without the need for tooling. It is possible to build internal features and passages that are not possible in conventional manufacturing routes. The process generates significant amount of condensate due to vaporization and suction applied to build chamber. Typically as much as 30% of the weight of powder ends up as condensate. The condensate so generated cannot be directly recycled. This results in significant reduction in profitability and process efficiency. This study pertains to 18% Ni Maraging Steel grade C300, which commonly used in DMLS process. Maraging Steel is used extensively to build functional parts by DMLS process especially for Tool and Die applications. In the present study chemistry, particle size distribution & morphology of the condensate was studied & compared with the powder. Parts were built using condensate and chemical, physical, mechanical, microstructure and XRD studies were done. These properties were compared with properties of parts built using fresh powder. No difficulty was encountered in building parts using condensate. However, hardness and tensile properties were found to be inferior, thus it is not possible to recycle the condensate directly. Present research investigates the cause of difference in these properties.

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