Analysis of Polished Surfaces of Titanium Castings

Abstract

Purpose The aim of this research was to obtain an objective grasp of the surface properties of titanium castings which are polished using a titanium polishing method developed by our university. Methods The specimens were cast conventionally using commercially pure (CP) titanium (Grade 3, T-alloy H, GC). The cast surfaces were polished using two methods ; a conventional procedure for mirror surfaces and a modified procedure consisting of minimal grinding foracceptable fit of the inner surface. The center line average roughness (Ra) wasmeasured, and then qualitative analysis and map analysis were performed using Electron Probe X-ray Microanalysis. In addition, map and line analysis on sections of the as-cast titanium specimens was performed, and the Vickers hardness of the surface was measured. As controls, Au-Pt alloy and Co-Cr alloy specimens were analyzed. Results The Ra on the titanium inner surface was 1.52 ,um, which was approximately four times higher than that on the mirror surface, and approximately two times higher than that for the Au-Pt alloy and Co-Cr alloy. The qualitative analysis of the titanium mirror surface detected elements such as C, Si, and Al as well as the ingot element. In addition, P was also detected on the titanium inner surface. The Vickers hardness was highest on the outermost surface layer, which decreased remarkably until a depth of 100-150 gm. Conclusions It was considered that the mirror surface formed by the titanium polishing method in our university obtained a level equivalent to that of precious metals. However, a reaction layer and elements derived from the investment material remained in the titanium inner surface.

Effects of surface roughness and tapered angle of cone crown telescopic system on retentive force

“…Moreover, the experimental cone crowns were made from Ti-6Al-7Nb alloy, which has not been reported previously. The surface roughness of the experimental prefabricated cone crowns was similar to that of the surface of CP Ti as cast or in the well-polished condition 35) . The retentive forces of commercial prefabricated cone crowns of 6° tapered angle were reported to range from 10.01 to 29.69 N 22) , and those prepared with CAD/ CAM CP Ti of 6° tapered angle were approximately 13 to 36 N 27) .…”

Effects of argon gas flow rate on laser-welding

“…Miura et al 21) measured the cross-sectional microhardness of the CP Ti cast plates at the depths of 0.03-0.6 mm from the as-cast surface. They found that the mean microhardness at the depth of 0.030 mm was 545 Hv, and decreased to 274 Hv at the depth of 0.1 mm 21) .…”

“…They found that the mean microhardness at the depth of 0.030 mm was 545 Hv, and decreased to 274 Hv at the depth of 0.1 mm 21) . However, for depths of 0.1-0.6 mm, the microhardness was almost constant 21) .…”

“…They found that the mean microhardness at the depth of 0.030 mm was 545 Hv, and decreased to 274 Hv at the depth of 0.1 mm 21) . However, for depths of 0.1-0.6 mm, the microhardness was almost constant 21) . In the present study, the mean microhardness of the cast specimens at 5.0 mm from the center was 225 Hv for an argon flow rate of 5 L/min and 269 Hv for 10 L/min.…”

“…Comparing these results with those of Miura et al , it seemed that about 0.1 mm of the as-cast surface region had been removed from the specimens. Miura et al 21) also carried out a qualitative analysis using EPMA for Ti polished using two different methods to produce a mirror surface and a rougher inner surface (such as for the inside of clasps). It was found that although Ti, O, N, C, Si and Al were detected from both surfaces, P was also detected from the inner surface 21) .…”