Tool Wear Inspection of Polycrystalline Cubic Boron Nitride Inserts

Abstract

Tooling used in machining of safety critical components are seldom used without highly frequent inspection. Worn or damaged tools produce undesirable surface finishes leading often to early failure of the part due to fatigue crack growth. In the development stages of polycrystalline boron nitride tools, an off-line run-to-failure method of tool wear inspection is undertaken which interrupts the cutting process intermittently to measure the tool wear using optical and scanning microscopy. The time consumption of this method leads to expensive tests and bottlenecks in the workshop. The overall aim in industry is to develop an on-line, automated system which is capable of informing the operator of the tool ′ s imminent failure. This paper focuses on treating this process as a preventative maintenance problem by studying whether acoustic emission can be used as an indirect measurement of tool wear at any given time. Acoustic emission measurements taken from the machining process of face turning are investigated here. Basic analysis in the frequency domain using principle component analysis reveals a number of interesting insights into the process. Relationships between the sharpness of the tool and the magnitude of the frequencies suggests promising link between acoustic emission and tool wear.

A sampling-based approach for information-theoretic inspection management

“…Suspending machining operations to inspect the cutting tool in a lathe during high-value manufacturing [7,8] .…”

“…measurements that arrive incrementally in (near) real-time [3,4]. Such data are increasingly prevalent in emerging applications of bridge monitoring [5,6], manufacturing [6][7][8] and wind power [9][10][11]. Here, the inspections must be managed and integrated, given online changes in the data, especially when excessive labelling fails to increase the understanding of the system condition.…”

Turning SKD 11 Hardened Steel: An Experimental Study of Surface Roughness and Material Removal Rate Using Taguchi Method

“…Due to their high melting point, excellent hardness, and resistance to wear, these inserts are able to withstand the high cutting temperature and cutting speed without failing. Polycrystalline cubic boron nitride (PCBN) and coated mixed ceramic tools have enabled industries and researchers to conduct dry turning operations for hard materials ranging from 50 to 65 HRC to achieve the required quality of machined parts [17][18][19]. While these advanced cutting tools exhibit high precision cutting capabilities, the manufacturing cost has correspondingly increased [20].…”