K. Shanker, B. Junkin, Standard Aero Ltd., Winnipeg, MB, Canada; J. Cuddy, Standard Aero Ltd, Winnipeg, MB, Canada
Cladding of titanium alloys using a laser as a heat source has been successfully used for a number of years. Much of this usage involves powder feed-stock and, in general, of a composition very similar to the base alloy being clad. While powders in a wide range of compositions are available, the large surface area of the powders and the cladding operation itself makes it difficult to ensure a low oxygen content in the cladding. Even small concentrations of oxygen can cause a significant decrease in the ductility of the cladding. Therefore, inert gas enclosures surrounding the cladding area are usually necessary, which is difficult when cladding large or complex shaped parts. The work presented in this paper investigates the use of Ti-6Al-4V wires as feed-stock; high purity Ti-6Al-4V wire in different diameters are readily available, making them ideal filler materials. The effect of laser cladding of two different titanium alloys (Ti-17 and Ti-5553) subject to different pre- and post- heat treatments will be presented, with particular emphasis on their tensile and impact properties. Both of these alloys are, like Ti-6Al-4V, mixed (a+b) phase alloys, but have compositions and b-phase contents that differ. Dense, crack- and pore- free claddings in excess of 3mm thickness x 25mm width are consistently obtained with wire feed-stock. The mechanical properties of the cladded material combination will be measured by tensile, bend and impact testing of test samples that are a composite of the base alloy and the clad layer, to simulate the mechanical properties of locally clad repaired parts. The bond tensile properties of cladded alloys will be measured using Ti-17 and 5553 laser welded together with Ti-6Al-4V wire, with the weld being transverse to the direction of testing. Welded and clad Ti-6Al-4V base alloys will be used for comparison.
Summary: Cladding of titanium alloys using a laser as a heat source has been successfully used for a number of years. Much of this usage involves powder feed-stock and, in general, of a composition very similar to the base alloy being clad. While powders in a wide range of compositions are available, the large surface area of the powders and the cladding operation itself makes it difficult to ensure a low oxygen content in the cladding. Even small concentrations of oxygen can cause a significant decrease in the ductility of the cladding. Therefore, inert gas enclosures surrounding the cladding area are usually necessary, which is difficult when cladding large or complex shaped parts. The work presented in this paper investigates the use of Ti-6Al-4V wires as feed-stock; high purity Ti-6Al-4V wire in different diameters are readily available, making them ideal filler materials. Also, previous work on laser cladding with wire demonstrated that simpler shielding is adequate with wire filler material.
The effect of laser cladding of two different titanium alloys (Ti-17 and Ti-5553) subject to different pre- and post- heat treatments will be presented, with particular emphasis on their tensile and impact properties. Both of these alloys are, like Ti-6Al-4V, mixed (ƒÑ+ƒÒ) phase alloys, but have compositions and ƒÒ-phase contents that differ. Dense, crack- and pore- free claddings in excess of 3mm thickness x 25mm width are consistently obtained with wire feed-stock. The mechanical properties of the cladded material combination will be measured by tensile, bend and impact testing of test samples that are a composite of the base alloy and the clad layer, to simulate the mechanical properties of locally clad repaired parts. The bond tensile properties of cladded alloys will be measured using Ti-17 and 5553 laser welded together with Ti-6Al-4V wire, with the weld being transverse to the direction of testing. Welded and clad Ti-6Al-4V base alloys will be used for comparison.
