Influence of palm stearin on powder injection moulding of stainless steel 316L

Experimental and theoretical analyses of mouldability for feedstocks used in powder injection moulding are performed. This study covers two main analyses. (i)The experimental analysis: the barrel temperature, injection pressure, and flow rate are factors for powder injection moulding (PIM). Powder-binder mixture used as feedstock in PIM requires a little more attention and sensitivity. Obtaining the balance among pressure, temperature, and especially flow rate is the most important aspect of undesirable conclusions such as powder-binder separation, sink marks, and cracks in moulded party structure. In this study, available feedstocks used in PIM were injected in three different cavities which consist of zigzag form, constant cross-section, and stair form (in five different thicknesses) and their mouldability is measured. Because of the difference between material and binder, measured lengths were different. These were measured as 533 mm, 268 mm, 211 mm, and 150 mm in advanced materials trade marks Fe–2Ni, BASF firm Catamould A0-F, FN02, and 316L stainless steel, respectively. (ii)The theoretical analysis: the use of artificial neural network (ANN) has been proposed to determine the mouldability for feedstocks used in powder injection moulding using results of experimental analysis. The back-propagation learning algorithm with two different variants and logistic sigmoid transfer function were used in the network. In order to train the neural network, limited experimental measurements were used as training and test data. The best fitting training data set was obtained with three and four neurons in the hidden layer, which made it possible to predict yield length with accuracy at least as good as that of the experimental error, over the whole experimental range. After training, it was found that theR2values are 0.999463, 0.999445, 0.999574, and 0.999593 for Fe–2Ni, BASF firm Catamould A0-F, FN02, and 316L stainless steel, respectively. Similarly, these values for testing data are 0.999129, 0.999666, 0.998612, and 0.997512, respectively. As seen from the results of mathematical modeling, the calculated yield lengths are obviously within acceptable uncertainties.

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SS 316L/HA composite via powder injection moulding: Mechanical and physical properties

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.13.3.2019.17.0443 ◽

2019 ◽

Vol 13 (3) ◽

pp. 5480-5492

Author(s):

N. A. Johari ◽

F. R. M. Romlay ◽

W. S. W. Harun

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Mechanical Strength ◽

Physical Properties ◽

Injection Moulding ◽

Powder Injection ◽

Stainless Steel 316L ◽

Bony Tissue ◽

Powder Injection Moulding ◽

Mechanical And Physical Properties

The bio-active and biological affinity with bony tissue effect of hydroxyapatite (HA) marks as a chosen material for implants application. Uniting HA which has low mechanical properties that limit its application with a higher mechanical property of metallic biomaterial 316L stainless steel (316L) to form a biocomposite have been a solution to produce acceptable mechanical properties for human implant. The 316L/HA biocomposite would have attribute vital to current implant materials, like a low Young’s modulus, high compatibility, and bio-inertness. This study concentrates on investigating the mechanical and physical properties of the 316L/HA biocomposite fabricated by metal injection moulding. The synthesis HA was produced from calcium-Phosphate. While, Polypropylene (PP), Stearin Acid (SA) and primary binder, Paraffin wax (PW) used as a binder system. Different weight of HA (0, 5, 10 and 15 wt. %) ratios to SS 316L/HA were prepared. All samples were sintered at 1350 ºC for 2 hours soaking time. The result shows that 10 wt.% HA biocomposite and above have higher porosity and low mechanical strength. However, 5 wt.% HA biocomposite has a high relative density which 87.95% compared to other additive HA % and hardness 127.10 Hv. The Tensile strength and elongation of 316L/HA biocomposite exhibit decreased as the content of HA wt.% increase which similar properties with the human bone that lower than 130 MPa (tensile strength). Therefore, 5 wt.% HA biocomposite is found to be the most excellent powder ratio for 316L/HA biocomposite regarding mechanical and physical properties and to achieve the mechanical strength of the biocomposite is necessary an amount of HA content in the composite are smaller than 15 wt.%.

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