Evaluation of chip formation mechanisms in the turning of sintered ZnO electro-ceramics

Dugar, Jaka (author), Ikram, Awais (author), Pušavec, Franci (author)

The sintered zinc oxide (ZnO) electro-ceramics are a brittle class of hard-to-cut materials such that shaping them with the post-finishing operations necessitates careful handling and precision machining. The conventional machining approach using the grinding and lapping processes represents limited productivity, an inability to produce the required geometries and frequent uncontrolled chipping of the edges of the final products. This study thus investigates the turning performance of dense sintered ZnO varistors and chip formations to obtain the parametric range (cutting mechanism) which causes the chipping or the trans-granular/sudden failure in these brittle materials. With the analysis of the cutting tool vibration in relation to the machining parameters (f and V$_C$), the vibration-induced chipping correlations are made and interlinked with the occurrence of grain pull-out during the turning operation. The results show that the reflected vibratory motion of the tools is directly correlated with the chip formation mechanisms in the turning of ZnO ceramics and thus provide robust measurements for quality assurance in final products.

• Language: English
• Keywords: ZnO varistors, machining optimization, turning, chipping, accelerometer, FFT plotting, 3D topography
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 20 str.
• Numbering: Vol. 9, iss. 8, art. 1422
• PID: 20.500.12556/RUL-132409
• UDC: 621.941(045)
• ISSN on article: 2227-9717
• DOI: 10.3390/pr9081422
• COBISS.SI-ID: 80316675
• Publication date in RUL: 25.10.2021

Record is a part of a journal

• Title: Processes
• Shortened title: Processes
• Publisher: MDPI AG
• ISSN: 2227-9717
• COBISS.SI-ID: 523353113

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 17.08.2021

Secondary language

• Language: Slovenian
• Keywords: ZnO varistorji, optimizacija parametrov obdelave, struženje, formiranje odrezkov

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: L2-8184
• Name: Razvoj in implementacija kriogenega odrezavanja v serijsko proizvodnjo za povečanje produktivnosti procesov vrtanja in frezanja

• Funder: ARRS - Slovenian Research Agency
• Project number: L2-1836
• Name: Razvoj in implementacija inovativne tehnologije obdelave ZnO keramike z definirano rezalno geometrijo v serijsko proizvodnjo za povečanje kakovosti varistorjev kot končnih izdelkov