Surface Quality Of Machined Workpiece Research Articles

Monitoring of Vibrations in the Technology of AWJ

Vibrations of cutting head act as co-factor causing striation of machined work-piece surface, deteriorating its surface quality. In this paper, measurement and evaluation of vibrations generated during the AWJ machining is performed using specialized diagnostic systems. In conclusion, means to minimize influence of cutting-head vibrations on the machined work-piece surface quality are discussed.

Development of a New BCB ELID Lapping Process

In this paper, the mechanism of Electrolysis In-process Dressing (ELID) lapping process using new BCB (bamboo charcoal bonded) abrasive wheel is researched. Some experiments of machining for silicon wafers were carried out for exploring the effect of some machining process parameters on material removal rate and surface roughness. Experiments show that: Material removal rate and machined workpiece surface roughness are increased with increase of the lapping wheel’s rotation speed and processing loading; The machined workpiece surface quality is affected with the lapping wheel surface condition, due to the abrasives are trued by electrolysis dressing in the lapping process, therefore the BCB lapping wheel always keeps better machining condition to obtain excellent machined workpiece surface quality efficiently.

Simulation of Particles Movement in Powder Mixed EDM

The particles dispersed in gap can increase the discharge stability and reduce discharge energy density in powder mixed EDM, which effectively improve the surface quality of machined workpieces. Concentration and distribution of particles computed by finite element methods in working conditions were simulated and corresponding experiments were done. The activities of particles in the discharge process were analyzed by experiments and theories. The results show particles have group effect in the gap and that the effect closely associates with particles concentration.

A cBN-TiN composite coating for carbide inserts: Coating characterization and its applications for finish hard turning

Cubic boron nitride (cBN)–titanium nitride (TiN) composite coating combines the thermal stability and super abrasiveness of cubic boron nitride (cBN) and the good lubricity of TiN, offering the opportunity for designing cutting tools with application specific new geometries (flat, chip breaker, and round shape) and cost effectiveness. In particular, the cBN based coating on carbide inserts is complementary to widely used polycrystalline cubic boron nitride (PCBN) compact tools for finish hard turning applications. This paper reports the results of a study addressing the surface morphology, surface roughness, coating cross section, chemical composition, crystal structure, microhardness, adhesion, and the wear life of this cBN-based coating deposited on carbide inserts (SNMG432) for finish turning of hardened AISI 4340 steel bars. The surface quality of machined workpieces in terms of their surface roughness and white layer formation are also analyzed and the results are presented.

Study of the ground workpiece surface topography in high-speed precision grinding using a scanning tunneling microscopy

High-speed and high-precision grinding technology can be used to improve the machined workpiece surface quality and surface finish. A study of the effect of machining parameters on the machined workpiece surface topography in high-speed precision grading using an electronic profiler and a scanning tuning microscopy (STM) is presented in this paper. Further, the micro-surface features are also described and analyzed with 3-dimensional parameters and fractal dimensions. It is found that the grinding speed ( V s) and dressing lead ( S d) have a significant influence on the grinding characteristics and the machined workpiece surface microtopography, with a “self-affinity” feature, and that different machining parameters correspond to different fractal dimensions at the micro-scale. The results indicate that it is possible to study high-speed precision grinding characteristics using STM at the nanometer scale.