偶翻《文摘周报》,一篇短文——《令人啼笑皆非的怪事》——引起了我的兴趣。一气读完,确实令人啼笑皆非。然而掩卷深思,却也悟出一些更深的道理。这篇文章说了这样一件怪事:西安某厂从英国进口了一批设备,其中有一种游标卡尺,质量好,...偶翻《文摘周报》,一篇短文——《令人啼笑皆非的怪事》——引起了我的兴趣。一气读完,确实令人啼笑皆非。然而掩卷深思,却也悟出一些更深的道理。这篇文章说了这样一件怪事:西安某厂从英国进口了一批设备,其中有一种游标卡尺,质量好,使用方便,但价格昂贵——每把四百元。然而使用时竟发现卡尺的末端印有“made in China”的字样。经查对后才知道是陕西省勉县国营硬质合金工具广的产品,问其售价仅六十三元。西洋镜揭穿。展开更多
Mar-M247 is a nickel-based alloy which is well known as difficult-to-machine material due to its characteristics of high strength, poor thermal diffusion and work hardening. Calculation of shear stress by an analytica...Mar-M247 is a nickel-based alloy which is well known as difficult-to-machine material due to its characteristics of high strength, poor thermal diffusion and work hardening. Calculation of shear stress by an analytical force model to indicate the effect of coating material, cutting speed, feed rate on tool life and surface roughness was conducted experimentally. Cutting tests were performed using round inserts, with cutting speeds ranging from 50 to 300 rn/min, and feed rates from 0.1 to 0.4 mm/tooth, without using cooling liquids. The behavior of the TiN and TiCN layers using various cutting conditions was analyzed with orthogonal machining force model. Cutting results indicate that different coated tools, together with cutting variables, play a significant role in determining the machinability when milling Mar-M247.展开更多
文摘偶翻《文摘周报》,一篇短文——《令人啼笑皆非的怪事》——引起了我的兴趣。一气读完,确实令人啼笑皆非。然而掩卷深思,却也悟出一些更深的道理。这篇文章说了这样一件怪事:西安某厂从英国进口了一批设备,其中有一种游标卡尺,质量好,使用方便,但价格昂贵——每把四百元。然而使用时竟发现卡尺的末端印有“made in China”的字样。经查对后才知道是陕西省勉县国营硬质合金工具广的产品,问其售价仅六十三元。西洋镜揭穿。
文摘Mar-M247 is a nickel-based alloy which is well known as difficult-to-machine material due to its characteristics of high strength, poor thermal diffusion and work hardening. Calculation of shear stress by an analytical force model to indicate the effect of coating material, cutting speed, feed rate on tool life and surface roughness was conducted experimentally. Cutting tests were performed using round inserts, with cutting speeds ranging from 50 to 300 rn/min, and feed rates from 0.1 to 0.4 mm/tooth, without using cooling liquids. The behavior of the TiN and TiCN layers using various cutting conditions was analyzed with orthogonal machining force model. Cutting results indicate that different coated tools, together with cutting variables, play a significant role in determining the machinability when milling Mar-M247.
