Grindability of cast Ti-Cu alloys.
OBJECTIVE
The purpose of the present study was to evaluate the grindability of a series of cast Ti-Cu alloys in order to develop a titanium alloy with better grindability than commercially pure titanium (CP Ti), which is considered to be one of the most difficult metals to machine.


METHODS
Experimental Ti-Cu alloys (0.5, 1.0, 2.0, 5.0, and 10.0 mass% Cu) were made in an argon-arc melting furnace. Each alloy was cast into a magnesia mold using a centrifugal casting machine. Cast alloy slabs (3.5 mm x 8.5 mm x 30.5 mm), from which the hardened surface layer (250 microm) was removed, were ground using a SiC abrasive wheel on an electric handpiece at four circumferential speeds (500, 750, 1000, or 1250 m/min) at 0.98 N (100 gf). Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1min. Data were compared to those for CP Ti and Ti-6Al-4V.


RESULTS
For all speeds, Ti-10% Cu alloy exhibited the highest grindability. For the Ti-Cu alloys with a Cu content of 2% or less, the highest grindability corresponded to an intermediate speed. It was observed that the grindability increased with an increase in the Cu concentration compared to CP Ti, particularly for the 5 or 10% Cu alloys at a circumferential speed of 1000 m/min or above.


CONCLUSIONS
By alloying with copper, the cast titanium exhibited better grindability at high speed. The continuous precipitation of Ti(2)Cu among the alpha-matrix grains made this material less ductile and facilitated more effective grinding because small broken segments more readily formed.
Kikuchi
Masafumi
M
Division of Dental Biomaterials, Department of Oral Rehabilitation and Materials Science, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, 980-8575, Sendai, Japan. kikuchi@mail.cc.tohoku.ac.jp
Takada
Yukyo
Y
Kiyosue
Seigo
S
Yoda
Masanobu
M
Woldu
Margaret
M
Cai
Zhuo
Z
Okuno
Osamu
O
Okabe
Toru
T
D017554:Carbon Compounds, Inorganic; D003300:Copper; D003722:Dental Alloys; D003735:Dental Casting Technique; D003775:Dental Polishing; D008422:Materials Testing; D008669:Metallurgy; D008855:Microscopy, Electron, Scanning; D017655:Silicon Compounds; D013499:Surface Properties; D014025:Titanium
D017554:Carbon Compounds, Inorganic; D003722:Dental Alloys; D017655:Silicon Compounds; D003300:Copper; D014025:Titanium; C022088:silicon carbide