Method for forming a golf club head or portion thereof with reduced porosity using hot isostatic pressing
A process for making a golf club head or a portion thereof with reduced internal flaws and/or improved mechanical properties is disclosed.
1 . A method for forming a cast metal component of a golf club comprising:
providing the cast metal component;
modifying the surface of the cast metal component to form a surface-modified cast metal component; and
treating the cast metal component in a hot isostatic pressing process to form a bulk-modified cast metal component.
2 . The method according to claim 1 , wherein the surface modification step comprises chemical milling.
3 . The method according to claim 1 , wherein the cast metal component is a club head insert, an iron club head, a driver club head, or a putter.
4 . The method according to claim 1 , wherein the cast metal component is made from stainless steel, titanium, or a titanium alloy.
5 . The method according to claim 1 , wherein the hot isostatic pressing process occurs at an elevated temperature, at an elevated pressure, in an inert atmosphere, and for a period of time, such that at least one of the following conditions is satisfied:
the elevated temperature is from about 800° C. to about 1200° C.;
the increased isostatic pressure is from about 400 kg/cm 2 to about 2000 kg/cm 2 ;
the period of exposure time at the elevated temperature and pressure is from about 0.5 hours to about 5 hours; and
the inert atmosphere comprises argon.
6 . The method according to claim 1 , wherein the hot isostatic pressing step minimizes the impact of at least one of the following flaws in the cast metal component: voids, porosity, undesirable metallic phases, undesirable ceramic phases, dislocation stresses, extensive grain boundaries, and combinations thereof.
7 . The method according to claim 1 , wherein the bulk-modified cast metal component exhibits increases in at least one of the following mechanical properties: tensile strength, flexural strength, toughness, impact resistance, low-cycle fatigue resistance, high-cycle fatigue resistance, creep life, strain-to-break, rupture stress, and combinations thereof.
8 . The method according to claim 1 , wherein the surface modification step comprises a chemical mechanical polishing step.