Powder bed binder jet printed alloy 625: Densification, microstructure and mechanical properties

Abstract

Powder bed binder jet printing is an additive manufacturing method in which powder is deposited layer-by-layer and selectively joined in each layer with binder. Since the powder does not melt during printing, the density after printing is about 50%, and sintering is needed to densify as-printed parts. In this study, we investigate the effect of sintering temperature on density, microstructure, phase formation and mechanical properties of power bed binder jet printed alloy 625 parts. To determine the sintering temperatures, the as-received powder was subjected to differential scanning calorimetry analysis, and printed samples were cured and sintered at various temperatures under high vacuum. Density measurements, elemental analysis, phase formation and microstructure of as-printed, cured and sintered samples were investigated compared with mechanical properties. Results indicate that a fully densified parts with densities of up to 99.6%, as well as favorable mechanical properties (hardness of up to 238 HV 0.1 and UTS of up to 612 MPa) may be obtained for the sample sintered at 1280 °C. It is concluded that alloy 625 produced by powder bed binder jet printing can achieve similar density and mechanical properties as cast alloy 625.

A Review on Binder Jet Additive Manufacturing of 316L Stainless Steel

“…Unlike PBF processes which apply laser or electron beam to melt metal powders, no power heat source involved during the BJ building process, thus BJ can work with a wide range of metals and is regarded as one of the most cost-effective AM techniques [5,12,14,26,31,32]. Furthermore, the surrounding powder sufficiently supports any overhanging geometry in the powder bed and eliminates the need for support structure design [5,27].…”

“…Furthermore, the surrounding powder sufficiently supports any overhanging geometry in the powder bed and eliminates the need for support structure design [5,27]. BJ printing process can be accelerated by increasing the number of print head nozzles [5,12]. Since the printing process performs at room temperature, no residual stress or distortion is introduced to the part due to thermal gradients [4,5,12,27].…”

“…BJ printing process can be accelerated by increasing the number of print head nozzles [5,12]. Since the printing process performs at room temperature, no residual stress or distortion is introduced to the part due to thermal gradients [4,5,12,27]. Unbonded powders are fully recyclable so that can be used [26].…”

3D printed metal molds for hot embossing plastic microfluidic devices

“…Printing takes place at room temperature while the consolidation of parts can take place uniformly in a high temperature furnace. Thus, BJP does not induce residual stress or distortions in the part [29]. A modified processing protocol was used to improve the part density and surface finish as previously reported [30, 31].…”

Powder-bed additive manufacturing for aerospace application: Techniques, metallic and metal/ceramic composite materials and trends

“…PB-AM with the high power beams is used for different group of materials: from light metals like Aluminum [5,6] and Titanium alloys [7][8][9][10], to steels [5,[11][12][13], and even refractory Tungsten [14], Tantalum [15], Inconel [16][17][18][19][20][21], high entropy alloys (HEAs) [22][23][24][25][26][27][28][29] and bulk metallic glass (BMG) materials [30][31]. In special literature, the term "additive manufacturing", in relation to both metallic materials and polymers, is more common than 3D-printing commonly used in the news popular literature.…”