| Popis: |
High-speed jetting technology has developed quickly over the past few decades.Since its first introduction in the early 1970s the number of applications has rapidly increased. Of the high-speed jet-based processes, cutting with an abrasive water jet (AWJ) is the most common. In this process, hard abrasive particles, which are accelerated by a high-speed water jet (WJ),can erode practically any known material. On the other hand, a plain WJ is used mostly for cutting softer materials, cleaning, surface preparation, applications in medicine and food processing. Recently, WJs have been used in forming, mostly as a tool for surface peening, but some research has shown great potential for a WJ as a tool for incremental sheet-metal forming (ISMF). In this study we analyzed the possibility to apply a high-speed WJ as a tool for ISMF. The importance of process parameters such as water pressure and volume flow were determined, and the most appropriate water-nozzle geometry was defined as well. A case study is included, where a simple geometry was incrementally formed by a WJ in 0.5-mm-thick aluminum-alloy plate. Compared to ISMF with a rigid tool, the proposed technology is more environmentally friendly, since no lubrication is required, and from our firstinvestigation it seems that the formability is increased as well. V zadnjih desetletjih je tehnologija obdelave s curki z velikimi hitrostnmi dozivela velik razvoj. Od prvih primerov uporabe v zgodnjih sedemdesetih letih prejsnjega stoletja se je uporaba močno povečala. Med vsemi postopki, ki temeljijo na uporabi curkov z velikimi hitrostmi, ima vodilno vlogo rezanje z abrazivnim vodnim curkom (AVC), pri katerem vodni curek z velikimi hitrostmi (VC) pospešuje trde abrazivne delce, ki razjedajo material obdelovanca. Po drugi strani se VC uporablja za rezanje mehkejših materialov, čiščenje, površinsko obdelavo ter za uporabo v medicini in živilski industriji. V zadnjem času se VC uporablja tudi pri preoblikovanju, predvsem za utrjevanje površine izdelka, nekaj raziskav pa je pokazalo, da ima VC velike moznosti kot orodje za postopno preoblikovanje pločevine (PPP). V tej raziskavi smo preučili moznosti uporabe vodnega curka z velikimi hitrostmi kot orodja za PPP. Prikazana je vplivnost postopkovnih parametrov kakor sta tlak in pretok vode, prav tako je definirana najbolj primerna geometrijska oblika vodne sobe za tvorbo curka. Predstavljen je tudi primer postopnega preoblikovanja 0,5 mm debele pločevine iz aluminijeve zlitine v preprosto obliko z VC. Med primerjavo PPP z orodjem z določeno obliko se izkaže, da je predlagana tehnologija ekološko bolj sprejemljiva, saj ni potrebe po uporabi mazalnih sredstev. Prve raziskave nakazujejo, da se izboljša preoblikovalnost pri uporabi VC kot orodja za PPP. |
