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Microcleanliness efforts result in low-inclusion nitinol for preserved strength and integrity

The size and distribution of inclusions plays a critical role in the quality of the nitinol used in your component or product. Memry’s longstanding experience in melting and processing nitinol is delivering significant improvements in microcleanliness.

Among the benefits of low-inclusion nitinol are preserved strength of the material. Memry’s melting and processing techniques protect the integrity of the nitinol, which becomes increasingly important as the medical device industry moves to smaller, lower profile devices with thinner structures.

Nitinol microcleanliness is rated by the presence of non metallic inclusions and porosity. Typical non-metallic inclusions are carbides (TiC) and intermetallic oxides (Ti4Ni2Ox). The ASTM F 2063 standard sets the maximum allowable dimension of inclusions at 39μm and the maximum area fraction at 2.8%.

Memry’s nitinol has a distinct advantage relative to microcleanliness as compared to the published ASTM standards.

Based on statistics from multiyear production data, Memry has demonstrated that the company’s typical maximum inclusion size is below 26 microns vs the ASTM standard of 39 microns. The typical area fraction of inclusions for Memry’s nitinol is below 2.0%, again improving upon the ASTM standard of 2.8%. Moreover, the distribution of inclusions in size shows that the average inclusion size is around 2 microns, with 99% of inclusions below 9 microns.

Distribution of Inclusions, With Size, C5-10064 Bar, All Inclusions

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Read more about nitinol inclusion testing protocol (PDF).