In this study, crystal grain refinement of pure titanium manufactured by electron beam melting through cryogenic rolling was performed. The effect of rolling in a cryogenic atmosphere on average grain size was investigated. Cryogenic atmosphere rolling was confirmed to be smaller than normal temperature rolling. Electron back scatter diffraction (EBSD) confirmed the presence of oriented crystal grains in the material. The deformation, temperature, and stress generated during rolling were calculated using 3D simulation. Finite element analysis (FEM) modeling was used to analyze the trend of average grain size change during the heat treatment of the rolled samples.

Design of gating system is an important factor in obtaining defect-free casting. One of the casting defects is a porosity caused by internal

shrinkage in solidification process. Prediction of the internal shrinkage porosity in the femoral stem of commercially pure titanium (CP-Ti)

is investigated based on the gating system design. The objective of this research is to get the best gating system between three gating

system designs. Three gating system designs of the femoral stem were simulated in an investment casting method. The internal shrinkage

porosity occurs on the largest part and near the ingate of the femoral stem. The gating system design that has ingates cross section area:

78.5; 157; and 128.5 mm2

has the least of the internal shrinkage porosity. This design has the most uniform solidification in the entire of

the femoral stem. An experiment is conducted to validate the simulation data. The results of internal shrinkage porosity in the three gating

system designs in the simulation were compared with the experiment. Based on the comparison, the trend of internal shrinkage porosity at

the three gating system designs in the simulation agrees with the experiment. The results of this study will aid in the elimination of casting

defect.