A novel and effective method for cryogenic milling of polytetrafluoroethylene
- PDF / 6,562,773 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 77 Downloads / 233 Views
ORIGINAL ARTICLE
A novel and effective method for cryogenic milling of polytetrafluoroethylene Yongquan Gan 1 & Yongqing Wang 1 & Kuo Liu 1
&
Lingsheng Han 1 & Qi Luo 1 & Haibo Liu 1
Received: 28 July 2020 / Accepted: 29 October 2020 # Springer-Verlag London Ltd., part of Springer Nature 2020
Abstract Polytetrafluoroethylene (PTFE) is a typical material widely used in bearing, gaskets, gears, etc. of many various fields such as aeronautics, astronautics, and military. Traditionally, PTFE is manufactured by molding process, which is suitable for processing of large quantities and standard parts. And a deburring treatment is necessary after molding. For small-scale or special shape products, molding techniques require new molds which need long time period. In contrast, machining method can meet the requirements more efficiently. However, the traditional machining is prone to produce machining defects such as edge fins and burrs. In this paper, a novel and effective method for cryogenic machining is proposed. According to the experiment results, the cryogenic machining can effectively restrain the production of machining defects and subsurface damage layer. And the mechanism of defect suppression in cryogenic machining is revealed by analyzing the change of molecular structure and properties with temperature. Keywords Cryogenic milling . Machining defects . Mechanism of defects suppression . Polytetrafluoroethylene (PTFE)
1 Introduction Polytetrafluoroethylene (PTFE) is a sort of high polymer which has high thermal resistance, self-lubrication, high hydrophobicity, high chemical stability, and so on. It has been widely applied in many components in aeronautics, astronautics, and military such as bearing, gaskets, gears, seals, and shield [1, 2]. Generally, molding techniques are used in producing high polymer products for the most part, such as compression molding, extrusion and injection molding. Nevertheless, traditional ways are inefficient when molding certain acquired shapes, a single, or small-scale product. The mechanical cutting of polymeric materials is more suitable for the above desires. Besides, deburring processes also required mechanical machining [3, 4]. However, most mechanical machining is hard to produce smooth or well-finished edges [5].
* Kuo Liu [email protected] 1
Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, Dalian 116024, China
Especially in polymers machining, burr formation, edge overcut, internal surface damage, and groove clogging easily appear in mechanical machining [6]. Cryogenic machining is widely spread as a sustainable process, offering new methods for producing superior products. Cryogenic cooling strategies are emerging as environmentally safe, alternative to conventional flood cooling in machining [7]. Liquid nitrogen is commonly used in cryogenic machining [8]. Nitrogen is an abundant gas in nature, which reduces post-machining cleaning and disposal. In addition, it is clean, nontoxic, un
Data Loading...
