scholarly journals Investigation of Sintering Shrinkage in Binder Jetting Additive Manufacturing Process

2017 ◽  
Vol 10 ◽  
pp. 779-790 ◽  
Author(s):  
Yujia Wang ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Sintering Shrinkage ◽  
Binder Jetting

scholarly journals Effect of Particle Size Distribution on Powder Packing and Sintering in Binder Jetting Additive Manufacturing of Metals

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Yun Bai ◽  
Grady Wagner ◽  
Christopher B. Williams
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Large Degree ◽  
Full Density ◽  
Powder Particle Size ◽  
Powder Mixtures ◽  
Fine Powders ◽  
Sintering Shrinkage ◽  
The Impact ◽  
Binder Jetting

The binder jetting additive manufacturing (AM) process provides an economical and scalable means of fabricating complex parts from a wide variety of materials. While it is often used to fabricate metal parts, it is typically challenging to fabricate full density parts without large degree of sintering shrinkage. This can be attributed to the inherently low green density and the constraint on powder particle size imposed by challenges in recoating fine powders. To address this issue, the authors explored the use of bimodal powder mixtures in the context of binder jetting of copper. A variety of bimodal powder mixtures of various particle diameters and mixing ratios were printed and sintered to study the impact of bimodal mixtures on the parts' density and shrinkage. It was discovered that, compared to parts printed with monosized fine powders, the use of bimodal powder mixtures improves the powder's packing density (8.2%) and flowability (10.5%), and increases the sintered density (4.0%) while also reducing the sintering shrinkage (6.4%).

Learning Algorithm Based Modeling and Process Parameters Recommendation System for Binder Jetting Additive Manufacturing Process

2015 ◽  
Author(s):  
Han Chen ◽  
Yaoyao F. Zhao
Keyword(s):  
Additive Manufacturing ◽  
Product Quality ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Process Model ◽  
Recommendation System ◽  
Powder Materials ◽  
Quality Properties ◽  
Binder Jetting ◽  
Printing Time

Binder Jetting (BJ) process is an additive manufacturing process in which powder materials are selectively joined by binder materials. Products can be manufactured layer by layer directly from 3D model data. It is not always easy for manufacturing engineers to choose proper BJ process parameters to meet the end-product quality and fabrication time requirements. This is because the quality properties of the products fabricated by BJ process are significantly affected by the process parameters. And the relationships between process parameters and quality properties are very complicated. In this paper, a process model is developed by Backward Propagation (BP) Neural Network (NN) algorithm based on 16 groups of orthogonal experiment designed by Taguchi Method to express the relationships between 4 key process parameters and 2 key quality properties. Based on the modeling results, an intelligent parameters recommendation system is developed to predict end-product quality properties and printing time, and to recommend process parameters selection based on the process requirements. It can be used as a guideline for selecting the proper printing parameters in BJ to achieve the desired properties and help to reduce the printing time.

Molecular Dynamics Simulation of Nanoparticle Infiltration During Binder Jet Printing Additive Manufacturing Process: A Preliminary Study

2019 ◽  
Author(s):  
Sagil James ◽  
Cristian Navarro
Keyword(s):  
Molecular Dynamics ◽  
Additive Manufacturing ◽  
Molecular Dynamics Simulation ◽  
Simulation Model ◽  
Manufacturing Process ◽  
Operating Temperature ◽  
Dynamics Simulation ◽  
Infiltration Process ◽  
Operating Temperatures ◽  
Binder Jetting

Abstract Binder Jetting Process involves binding layers of powder material through selective deposition of a liquid binder. Binder jetting is a fast and relatively inexpensive process which does not require a high-powered energy source for printing purpose. Additionally, the binder jetting process is capable of producing parts with extreme complexities without using any support structures. These characteristics make binder jetting an ideal choice for several applications including aerospace, biomedical, energy, and several other industries. However, a significant limitation of binder jetting process is its inability to produce printed parts with full density thereby resulting in highly porous structures. A possible solution to overcome the porosity problems is to infiltrate the printed structures with low-melting nanoparticles. The infiltrating nanoparticles help fill up the voids to densify the printed parts and also aids in the sintering of the printed green parts. In addition to increasing the density, the nanoparticle infiltration also helps improve the mechanical, thermal and electrical properties of the printed part along with bringing multi-functionality aspect. Currently, there is a lack of clarity of the nanoparticle infiltration process performed to improve the quality of parts fabricated through binder jetting. This research employs Molecular Dynamics simulation techniques to investigate the nanoparticle infiltration during binder jetting additive manufacturing process. The simulation is performed at different operating temperatures of 1400 K, 1500 K, and 1600 K. The study found that the infiltration process is significantly affected by the operating temperature. The infiltration height is found to be highest at the operating temperature of 1600 K while the porosity reduction is found to be maximum at 1500 K. The infiltration kinetics is affected by the cohesion of the nanoparticles causing blockage of channels at higher operating temperatures. The simulation model is validated by comparing with the Lucas-Washburn infiltration model. It is seen that the simulation model deviates from the theoretical prediction suggesting that multiple mechanisms are driving the infiltration process at the nanoscale.

scholarly journals Structure and Properties of Barium Titanate Lead-Free Piezoceramic Manufactured by Binder Jetting Process

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4419
Author(s):  
Vadim Sufiiarov ◽  
Artem Kantyukov ◽  
Anatoliy Popovich ◽  
Anton Sotov
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Barium Titanate ◽  
Manufacturing Process ◽  
Lead Free ◽  
Density Values ◽  
Binder Saturation ◽  
Binder Jetting ◽  
Titanate Lead ◽  
Functional Ceramics

This article presents the results of manufacturing samples from barium titanate (BaTiO3) lead-free piezoceramics by using the binder jetting additive manufacturing process. An investigation of the manufacturing process steps for two initial powders with different particle size distributions was carried. The influence of the sintering and the particle size distribution of the starting materials on grain size and functional properties was evaluated. Samples from fine unimodal powder compared to coarse multimodal one have 3–4% higher relative density values, as well as a piezoelectric coefficient of 1.55 times higher values (d33 = 183 pC/N and 118 pC/N correspondingly). The influence of binder saturation on sintering modes was demonstrated. Binder jetting with 100% saturation for both powders enables printing samples without delamination and cracking. Sintering at 1400 °C with a dwell time of 6 h forms the highest density samples. The microstructure of sintered samples was characterized with scanning electron microscopy. The possibility of manufacturing parts from functional ceramics using additive manufacturing was demonstrated.

scholarly journals Blade Segment with a 3D Lattice of Diamond Grits Fabricated via an Additive Manufacturing Process

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Bin Chen ◽  
Peng Chen ◽  
Yongjun Huang ◽  
Xiangxi Xu ◽  
Yibo Liu ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Service Life ◽  
Manufacturing Process ◽  
Cutting Speed ◽  
Inspection System ◽  
Layer By Layer ◽  
Filling Rate ◽  
Pressure System ◽  
Manufacturing Equipment ◽  
Diamond Blade

Abstract Diamond tools with orderly arrangements of diamond grits have drawn considerable attention in the machining field owing to their outstanding advantages of high sharpness and long service life. This diamond super tool, as well as the manufacturing equipment, has been unavailable to Chinese enterprises for a long time due to patents. In this paper, a diamond blade segment with a 3D lattice of diamond grits was additively manufactured using a new type of cold pressing equipment (AME100). The equipment, designed with a rotary working platform and 16 molding stations, can be used to additively manufacture segments with diamond grits arranged in an orderly fashion, layer by layer; under this additive manufacturing process, at least 216000 pcs of diamond green segments with five orderly arranged grit layers can be produced per month. The microstructure of the segment was observed via SEM and the diamond blade fabricated using these segments was compared to other commercial cutting tools. The experimental results showed that the 3D lattice of diamond grits was formed in the green segment. The filling rate of diamond grits in the lattice could be guaranteed to be above 95%; this is much higher than the 90% filling rate of the automatic array system (ARIX). When used to cut stone, the cutting amount of the blade with segments made by AME100 is two times that of ordinary tools, with the same diamond concentration. When used to dry cut reinforced concrete, its cutting speed is 10% faster than that of ARIX. Under wet cutting conditions, its service life is twice that of ARIX. By applying the machine vision online inspection system and a special needle jig with a negative pressure system, this study developed a piece of additive manufacturing equipment for efficiently fabricating blade segments with a 3D lattice of diamond grits.

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