LOW-CYCLE FATIGUE OF TITANIUM 6AL-4V SURGICAL TOOLS

A handle holder is used in heart valve replacement surgery to insert a mechanical flow valve into the patient's heart. In order to position the valve correctly, a 0.1 '' diameter titanium 6Al-4V handle holder s haft is bent until the proper angle is found. This bending of the tool makes it vulnerable to low-cycle fatigue failure. Low cycle fatigue t esting of titanium 6Al-4V specimens shows that surface cracks appear a pproximately 20 cycles before failure occurs. It is recommended that t he tool be carefully inspected before each use and replaced when surfa ce cracks appear. The data showed that the life of the tool may be inc reased by 30% if it is bent in the same direction during its entire us e. (C) 1998 Elsevier Science Ltd. All rights reserved.