Dynamic fracture characteristics are important for the application of titanium and its alloys in various industrial fields. The fatigue properties of metal injection molded (MIM) titanium and Ti-6Al-4V * compacts were evaluated. Fatigue strength in rotating bending was found to be about one-third of the static tensile strength; this is attributed to cracking initiated at surface pores. With the addition of chromium or TiB2 to Ti-6Al-4V, the sintered compacts exhibited a fine grain size, resulting in higher fatigue strength. Hot isostatic pressing (HIP) was used to further consolidate chromium-containing Ti-6Al-4V, resulting in ≥99% of the pore-free density (PFD) and an attendant fatigue strength >350 MPa. Crackpropagation behavior was studied by surface replication of Ti-6Al-4V specimens containing chromium at 80% fatigue life to understand the role of residual porosity. Surface cracks were present running from pore to pore, thereby limiting fatigue strength.
|Number of pages
|International Journal of Powder Metallurgy
|Published - 2014
All Science Journal Classification (ASJC) codes
- Metals and Alloys
- Industrial and Manufacturing Engineering