Effect of carnauba wax as a part of feedstock on the mechanical behavior of a part made of 4605 low alloy steel powder using metal injection molding

Abstract

Metal injection molding is a growing technology for producing complex metallic components. Preparation of feedstock for metal injection molding is a very crucial step during this process. This is because the deficiencies in quality of the feedstock once made, cannot be corrected by subsequent processing steps. One of the challenges in producing the feedstock is its formulation. In this study, the effect of the percentage of carnauba wax along with other binder constituents of paraffin wax, polypropylene and stearic acid is investigated on the density, strength, hardness and rheological behavior of a part, made of 4605 low alloy steel powder using metal injection molding process. For this reason, six binder systems including paraffin wax, polypropylene and stearic acid having different percentages of carnauba wax have been produced. After preparation of the samples, tensile testing, Vickers hardness test, density and rheological behavior of the samples have been measured and compared. The results show that carnauba wax as a part of feedstock, has a positive effect on the strength and density while negative effect on the hardness of the final sintered part. Also with the increase in the percentage of the carnauba wax inside the polymer binder, the viscosity of the feedstock was reduced significantly.

Effects of Bonding Treatment and Ball Milling on W-20 wt.% Cu Composite Powder for Injection Molding

“…The mixing torque is the feedback of energy consumed by the powder dispersed in the adhesive, indicating the viscosity of the mixture. Therefore, evaluating the critical powder loading by monitoring the torque variation during the feedstock mixing is a conventional method [ 33 , 34 ]. The variation of mixing torque with powder loading of feedstock is shown in Figure 4 .…”

Research Progress on Low-Pressure Powder Injection Molding

“…Generally, finer powders have been used for ceramics, making it more challenging to use backbones in most cases of this process. CW, a natural wax formed on Brazilian palm leaves, can play an essential role in developing proper binder systems for LPIM due to its great potential in particle wetting, gradual division of the debinding process, and lubrication [5,120]. According to the melting temperature, degradation behavior, and viscosity, CW could be a reliable alternative for the backbone in LPIM because it helps to retain the shape during thermal debinding.…”

“…Powder injection molding (PIM) is a manufacturing technology used to create smallto-medium-sized, highly complicated geometric components with remarkable dimensional and high precision at high production volumes [1][2][3][4]. This process comprises metal injection molding (MIM) and ceramic injection molding (CIM) [5] and uses metal or ceramic powder and polymer binder as raw materials. Binder systems are polymer-based multicomponent mixtures that play a crucial role in the manufacturing and defining of the PIM-produced products' final qualities [6,7].…”

Effect of polypropylene as the backbone of MIM feedstock on the micro-structural phase constituents, mechanical and rheological properties of 4605 low alloy steel compacts

“…Carnauba wax (CW), a natural wax formed on Brazilian palm leaves, acts as a lubricant and mould releasing agent inside the feedstock. It also helps in particle wetting and gradual division of the debinding process [12][13][14]. This material is an important part of the binder system in many CIM (Ceramic Injection Moulding) and MIM feedstocks [15].…”

“…In some studies, CW has also been used as a backbone polymer. This is due to the high degradation range of this wax [14]. It has been shown that the percentage of CW has a direct relation with the mechanical properties of the final MIM compact till a certain point after which with the increase in the percentage of CW, the mechanical properties start to decrease [16].…”