Phase Transformations in Metals

In Chapter 2 of Nitinol: The Book, Tom introduces some basics principles of phase transformations in metals. As unusual as Nitinol is, the superelastic and shape memory properties driving these are a byproduct of phase transformations that are ubiquitous in virtually all materials. Read on to learn more, including why Napoleon's Russian invasion failed because of a phase transformation... ...continue reading

SMST-2010: The Effect of Material Removal on the Corrosion Resistance of Laser-cut and Wire-form Products

In this SMST-2010 presentation, Jennifer presents data comparing the corrosion and biocompatibility performance of wire formed and laser cut stents having virtually identical starting geometry. Both groups were electropolished to remove <5%, <10%, and <25% material. Results indicate that the corrosion resistance increases with the amount material removal, and less material removal is required for ...continue reading


About two years ago, in May 2008, NDC regained its independence as a privately held company. To celebrate our one year anniversary, in May 2009, we launched a new brand identity and website at This year, for our two year anniversary, we introduce a new feature of the website, ...continue reading

The Future

What does the future hold for Nitinol? In this chapter, Tom speculates about the potential of shape memory applications, R-phase, and such emerging technologies as thin-film constructs, and porous Nitinol. ...continue reading

Other Alloys Exhibiting Shape Memory Effects

Other alloys exhibiting shape memory effects, including beta-titanium, brass, bronze, and nickel-aluminum. ...continue reading

A Historical Perspective

The history of steel dates thousands of years to ancient times, stainless steel has been prominent for about a hundred years, and Nitinol for perhaps a couple of decades. In this short chapter, Tom traces the ancestors of modern nickel titanium, dating to the 1930's. ...continue reading

A Short Orientation

The "shape memory triangle" introduces the concepts of shape memory and superelasticity effects in Nitinol. This quick installment includes the first of many figures that we'll refer to in this series. ...continue reading

Nitinol: The Book. An Introduction

Today we introduce an exciting new original series to Over twenty years have passed since the famously out-of-print Engineering Aspects of Shape Memory Alloys was published. In the subsequent decades, Tom Duerig, Alan Pelton, and colleagues here at NDC have learned quite a bit, and we’ve set out to write it all down in ...continue reading

Self Expanding Nitinol Stents

By the year 2003, Nitinol stents played a dominant role in the treatment of peripheral vascular disease. A great variety of designs had been launched into clinical service, some more successfully than others. This review was authored by the familiar NDC trio of Dieter Stoeckel, Alan Pelton, and Tom Duerig, and published in European Radiology. ...continue reading

SMA – Smart Materials for Medical Applications

In this paper from the proceedings of SPIE, Tom Duerig, Dieter Stoeckel, and David Johnson present some basic information on the properties of superelasticity and shape memory exhibited by Nitinol. The authors describe vascular applications including stents and filters, and some testing and characterization techniques applicable to such devices. This paper is notable in its ...continue reading