Problem Set 1

EMA 4714 - Materials Selection and Failure Analysis

Monday, January 7, 2008 [Due Wednesday, January 16, 2008]

In class, we have considered selection of materials for face plates of golf clubs - the objective in mind by the designer is, among other things, to maximize distance traveled by the ball from a given amount of energy input produced by the swing. Two reference sources were considered, both involving product application divisions of commercial concerns - Carpenter Technology and Liquid Metal Technologies. Each bases material performance on different criteria for performance as well as different material properties.

1. Explain, derive or otherwise defend the statement [Carpenter], “Assuming that the distance a golf ball is driven relates to the hardness and tensile strength of the face insert, more of the energy of the swing should be transferred to the ball with the two aerospace alloys.”

2. Explain, derive or otherwise defend the statement [Carpenter, page 90, 2nd paragraph up from the end of the page], “The three steels in the group of four metals studied have approximately 70% higher stiffness or modulus of elasticity than the Ti-6Al-4V alloy (Fig.3). Therefore, they are stiffer and support a greater load. As a result, inserts of those high-modulus, high-strength alloys will absorb less energy at the point of impact than titanium, and thus transfer more energy to the ball.”

3. Explain, derive or otherwise defend the statement [Liquidmetal], “A perfectly elastic sphere would show load being proportional to displacement raised to the 3/2 power identically upon loading and unloading.”

Please note that the document which you are submitting to management is to be the output of your group and be of quality befitting a professional - i.e. typed! No assignments will be accepted after the deadline no matter how legitimate you feel the excuse might be - no exceptions!