Effect of binders on mechanical properties in binder jetting metal additive manufacturing

With the development of new manufacturing methods with the Industry 4.0 revolution, solutions have been found for some of the disadvantages encountered in traditional manufacturing methods. One of these new manufacturing methods is the Binder Jetting Additive Manufacturing method. In this method, two raw materials are used. The first of these is the powder raw material and the other is the binder consisting of Organic or Inorganic components. Since it is a new and developing manufacturing method, the number of studies made is limited. Beside this, limited information sharing by commercial companies provides narrow opportunities for scientific research. In the Binder Jetting Additive Manufacturing method, the binders used are in either solid or liquid form. Liquid binders generally consist of a mixture of adhesives and chemicals. Liquid binders are selectively sprayed onto the powder using a binder inkjet cartridge. For the binders to be sprayed from the cartridge, their rheological properties (pH, viscosity, surface tension, etc.) must fall within the technical specifications of the cartridge. Therefore, liquid binders are obtained through the mixing of various chemical materials and adhesives under specific conditions. In this study, a binder jetting cartridge with a capacity of approximately 40 milliliters of liquid was utilized. In this thesis, potential binders for the method were created using various chemicals. Using these binders, samples were manufactured using the Binder Jetting Metal Additive Manufacturing method. Bending and compression tests were conducted on these samples. In manufacturing process SS316L powder was used as metal powder raw material. The curing conditions have been determined to achieve sufficient green strength for the transportation of the samples. Thermogravimetric analyzes were performed to determine debinding conditions. To examine the effect of binders on mechanical properties, three-point bending strength test, compressive strength test and density measurement were performed on raw samples, compressive strength test, density and microhardness measurements and carbon analysis were performed on sintered samples. In addition, composition ratios and diffraction patterns of the samples were analyzed through optical and scanning electron microscopy. Seven different adhesives were used in the study and positive results were obtained from binders created separately with two adhesives. The results obtained were compared with the recent literature results.