Grad student puts heart into stent research

Ali Raza, an Engineering graduate student, studied the corrosion behavior of additively manufactured (AM) Cobalt Chrome (CoCr) in heart stents. Additive manufacturing is a process of 3D printing metals, like Cobalt Chrome, to create products such as the stents used to hold open arteries.

The heart stents must not initiate or promote any inflammation after being inserted. The CoCr alloy has high corrosion resistance, however, the pH of blood plasma varies around a wound or at the site of the implant, so the corrosion behavior of these implants will also change. Sodium sulphate (Na2SO4) was used as a testing solution to mimic human blood plasma. To make the solution more aggressive and to replicate the service condition of the implant, Raza added a small quantity of chloride ions to the solution.  

Raza’s goal was to investigate the corrosion behavior of AM CoCr alloys in aggressive conditions and to find the range of pH in which the implant would be stable with or without chloride ions. Raza says, “This range of pH would not only be helpful in developing more implant materials but will also be helpful in preparing the CoCr implant against harsh conditions before implantation so that the implant does not need to be replaced after a period of time – 10-15 years for normal implants.”

Previously, Raza worked on a project studying titanium dental implants which analyzed corrosion and biocompatibility by growing biological cells on the modified alloy. This project inspired Raza to continue studying more implant materials and their corrosion properties.  

After graduation, Raza plans to work in the Materials Science industry to see his efforts executed at a national level.

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