Effect of 2 wt.% Addition of Fe on the Compressive Properties and Corrosion Behavior of Zn-HAp-Fe Material

Abstract

The present work deals in developing new zinc-based composite material for bone repair using a powder metallurgy process. Zinc (Zn), hydroxyapatite (HAp), and iron (Fe) powders were mechanically mixed with ball milling. Subsequently, the powder mixture was compacted to form the green compact. After that, the green compacts were sintered using a microwave sintering furnace. The mechanical and electrochemical behaviors of the prepared Zn-based samples were tested as per the standards. X-ray diffraction and energydispersive spectroscopic examinations revealed the existence of HAp and Fe in the Zn matrix. The compressive yield strength and compressive strength of the developed Zn-5HAp-2Fe material were found to be 117.91 ± 7.42 and 170.87 ± 7.41 MPa, respectively. In vitro electrochemical corrosion analysis of the developed Zn-5HAp-2Fe sample in simulated body fluid solution unveiled the corrosion rate as 0.116 ± 0.021 mmAEyear -1 . The mechanical and degradation behaviors of Zn-5HAp-2Fe material showed the potential to be used as a bone fixation material.

Experimental investigation and empirical modeling for corrosion rate prediction of biodegradable zinc based composite considering the effect of constituent materials

“…The major reason for the decreased density of the samples was the densities of the constituent materials (i.e., HA = 3.16 g/cm 3 , and Fe = 7.86 g/ cm 3 ). 34 However, it may be observed from Table 1 that samples having only HA possess a lower density as compared to samples that possess both HA and Fe as the density of Fe is immensely more than that of HA. Moreover, it may be noted that the products prepared using powder metallurgical techniques always produce microvoids.…”

“…The major reason for this change is the slowness of Fe in getting corroded under physiological environment. 34 The EDS spectrum analysis, as shown in Figure 7(a), revealed the presence of each constituent material (i.e., HA and Fe) in the Zn matrix before corrosion measurements. Besides, the primary integrals (i.e., Zn, O, P, and Ca) of the corrosion products after the corrosion testing can be seen in Figure 7(b).…”

“…However, in the Zn3HA2Fe sample, two peaks of the intermetallic compound (Zn 11 Fe) were also identified in the diffraction angle ranging from 42 to 44°, thus exhibiting Fe existence. 16,34 Therefore, it may be inferred that the microgalvanic effect after the addition of Fe could produce a higher corrosion rate with increased wt% of Fe. 16,44 However, the addition of Fe was also resulted in a lower corrosion rate compared to the samples having only HA with Zn.…”

“…Inline with this, Pathak and Pandey developed a new ZnHAFe composite, which had a good agreement of the compressive strength with the cortical bone. 33,34 However, alloying/reinforcement of other elements resulted in the altered corrosion rate of Zn based alloys and composites compared to pure Zn. Yang et al 30 presented the in vitro and in vivo studies of ZnHA composites.…”

“…According to the studies, Zn3HA and Zn5HA2Fe composites were found to possess a higher corrosion rate than pure Zn. 33,34 Therefore, an appropriate model is expected for predicting ZnHA and ZnHAFe materials' corrosion rate to further attain a wanted degradation rate. In the model for corrosion rate, appropriate controlling parameters such as corrosion current, equivalent weight, and material density were required to be deemed.…”