Cutting characteristics of bulk metallic glass
Cutting characteristics of bulk metallic glass
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DOI：
10.2320/matertrans.46.2856
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发表时间：
2005-12-01
影响因子：
1.2
通讯作者：
Inoue, A
中科院分区：
文献类型：
--
作者：
Fujita, K;Morishita, Y;Inoue, A
大块金属玻璃（BMG）具有优异的机械、物理和化学性能，因此需要建立适当的加工技术来应用大块金属玻璃（BMG）。在本报告中，通过使用不同刀具材料、刀尖半径 (R-H) 和切削速度 (V) 进行车削，检查了 BMG 的切削特性。使用 Zr65Cu15Ni10Al10 和 Pd40Cu30Ni10P20 at% BMG 圆棒作为工件。为了比较 BMG 与晶体合金的可切削性，使用了钢 (JIS SGD-400D) 和易切削黄铜 (JIS C3604)。测量加工表面的主切削力（F-H）和表面粗糙度（R-a）。还从加工表面获得了 X 射线衍射图案。 BMG 中的 R-a 值表现出精密精加工水平的上限（即 R-a = 0.2μm），尽管 V 值较高，但与钢相比显着较低，与易切削黄铜相比略低。该值随着 R-n 值的增加而变小，对于 1.2mm 的 R-n 值，表现出 0.08μm 的非常低的值。尽管 BMG 的拉伸强度是钢的两倍，但两种 BMG 的 FH 值没有显示出明显的差异，并且当 V 值小于 40 m/min 时，FH 值是钢的一半。 BMG 的芯片表现出理想的流动类型，具有非常短且规则的间隔，由平面滑移形成，并显示出非常均匀、平坦且无特征的背面。从这些对切屑的观察来看，推测 BMG 具有优异的可切割性的原因是由于非常短间隔的平面上的滑脱机制，该滑脱机制仅由最大剪切应力和低玻璃化转变温度引起的非积屑瘤决定。
The establishment of appropriate machining techniques for bulk metallic glasses (BMGs), which exhibit excellent mechanical, physical and chemical properties, is required to apply the BMGs. In this report, the cutting characteristics of BMGs were examined by turning with different tool materials, nose radii (R-H) and cutting speeds (V). Round bars of Zr65Cu15Ni10Al10 and Pd40Cu30Ni10P20 at% BMGs were used as the workpieces. In order to compare the cuttability of the BMGs with that of crystalline alloys, steel (JIS SGD-400D) and free-cutting brass (JIS C3604) were used. The principal cutting force (F-H) and surface roughness (R-a) of the machined surfaces were measured. X-ray diffraction patterns were also obtained from the machined surfaces. The value of R-a in the BMGs exhibit the upper end of precise finishing level (i.e., R-a = 0.2 mu m), and was remarkably lower compared with the steel and a little lower compared with the free-cutting brass in spite of the value of V. The value became smaller with increasing values of R-n, exhibiting a very low value of 0.08 mu m for an R-n value of 1.2 mm. The values of FH in both BMGs did not show a clear difference and were half that of the steel for a V value less than 40 m/min, even though the tensile strength of the BMGs was twice as large as the steel. The chip of the BMGs showed an ideal flow type with very short and regular intervals, formed by planar slip, and revealed very homogeneous, flat and featureless back surfaces. From these observations of chips, it is presumed that the reason for the excellent cuttability of BMGs is due to a slipping-off mechanism at planes of very short intervals decided only by the maximum shear stress and non-built-up edges caused by a low glass transition temperature.