Papers by Author: Hua Li Zhang

Abstract: Nanomachining tests have been conducted on single-crystal Al using atomic force microscope to simulate single-blade machining process of single gain. The influences of nanomachining experimental parameters (lateral feed and velocity) on the properties of engineering surface, material removal and chip formation were studied. Results indicated that the cutting depth of nanomachined surface increased as the lateral feed decreased. Insensitivity of cutting depth to velocity at same normal load was revealed. The different chip behaviors of nanomachined surface were investigated through scanning electron microscope (SEM). Results indicated that different lateral feeds caused different chip behaviors. Three typical chip behaviors were characterized as the lateral feed increased. In addition, the chip behavior and the volume of material removed were observed having no evident linear transformation with the evolution of the velocity by SEM graphics. Furthermore, it was concluded from the chip behaviors in nanomachining process that the material at high loads was removed by plastic deformation with no fracture or crack happened.

Abstract: Nano-cemented carbide is a novel material, which is superior to common cemented carbide on physical and mechanical properties, such as high hardness, toughness, flexural strength and higher wear resisting property. It is proposed to have wide application prospect to tools and mould manufacturing. In this paper, ELID grinding technique is applied to grind nano-cemented carbide tools. And the ground surface quality, cutting edge radius, and machinability of nano-cemented carbide tools are studied, compared with common cemented carbide. It is demonstrated by experimental results that nano-cemented carbide has higher grinding surface quality with less surface flaw than that of common cemented carbide. The cutting edge radius of nano-cemented carbide tool is less than that of common cemented carbide tool. Under the same conditions, the tool life of nano-cemented carbide is 1~2 times longer than that of common cemented carbide. The research results indicate that ELID grinding technique is suitable for grinding cemented carbide tools. Nano-cemented carbide tools have better machinability than common cemented carbide tools.

Abstract: Nano cemented carbide is a new style cutter material. Because its grain size is very small, it is superior to common cemented carbide in properties, such as high hardness, fracture toughness, flexural strength and higher abrasion resistance. As a cutter material, nano cemented carbide has wide use. In this paper, nano cemented carbide tool was ground with ELID technology, and the cutting properties of nano cemented carbide were studied, and the difference in cutting properties among the ultra-fine grain, common cemented carbide and nano cemented carbide was analyzed under the same condition. Results imply that the ground surface roughness of nano cemented carbide is obviously lower than that of common cemented carbide, and the tool life of nano cemented carbide is 5-7 times longer than that of common cemented carbide at low cutting speed.