Failure Analysis of a Titanium Golf Club Head
- PDF / 869,514 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 39 Downloads / 202 Views
CASE HISTORY—PEER-REVIEWED
Failure Analysis of a Titanium Golf Club Head Richard P. Baron • Raymond J. Claxton
Submitted: 20 September 2010 / in revised form: 23 September 2010 / Published online: 26 October 2010 Ó ASM International 2010
Abstract This article details the investigation of a failed head of a golf club driver that developed multiple cracks during normal use. The golf club head was manufactured from a titanium alloy, and the analysis revealed a progressive failure initiated on the interior surface of the club head face plate at a deep, concentric groove created from a forming during manufacturing. In addition, the welding operation used to assemble the head permitted contamination and, consequently, embrittlement, which could have also contributed to the failure of the golf club head. Keywords Failure analysis Fatigue cracking Titanium alloy Weld
Introduction The relative low density, high strength, and corrosion resistance of titanium alloys make them well-suited materials of construction for golf club driver heads. Titanium’s high strength-to-weight ratio allows for large driver heads that still meet the weight requirements of approximately 200 g. For example, titanium alloy driver heads can be made as large as 500 cm3, whereas the maximum size for high-density steel heads with the same weight is approximately 320 cm3. In addition, compared to common steel alloys, titanium alloys also exhibit a higher strength-tomodulus ratio, meaning a greater spring face performance. In general, titanium alloys are very sensitive to surface damage, as a dramatic reduction in fatigue properties can
R. P. Baron (&) R. J. Claxton Materials Analysis, Inc., Dallas, TX, USA e-mail: [email protected]
123
result if conventional machining operations are not carefully controlled. In addition, when welding alpha–beta titanium alloys, shielding atmospheres are required to inhibit weld contamination and the development of brittle structures. Titanium alloy driver heads are hollow shells constructed from three or four separate forged pieces that are welded together [1]. Due to the different property requirements for these areas of the club heads, several different titanium alloys can be used in combination to fabricate a single club head. Still, one of the most commonly used alloys is Ti–6Al–4V, which is a readily available alpha–beta titanium alloy. Reportedly, the subject golf club was relatively new but had been used approximately 100 times over a period of 6 months. The club may have been used once after an audible crack was heard.
Visual Examination The as-received golf club was initially visually examined (Fig. 1), revealing the presence of two transverse cracks in the 460 cm3 driver club head (Fig. 2). The crack in the club head face was located near the center of the striking surface; and, although it extended into the ends of the machined transverse grooves, it did not traverse along the entire club face. The second crack was located along the top surface of the club head, or crown, and extended t
Data Loading...
