12 research outputs found
Electrospark deposition for die repair
The electrospark deposition is a process for surfacing of hard metal alloys, e.g. carbides and stellites, on the surfaces of new or old machine elements. In this process, a high current is conducted through an oscillating electrode and a substrate for a very short period of time. In the paper, the process is described and the thickness of deposited layer, chemical composition, dilution rate and the layer roughness are determined
NanoÅ”enje elektriÄnom iskrom za popravak alata
The electrospark deposition is a process for surfacing of hard metal alloys, e.g. carbides and stellites, on the surfaces of new or old machine elements. In this process, a high current is conducted through an oscillating electrode and a substrate for a very short period of time. In the paper, the process is described and the thickness of deposited layer, chemical composition, dilution rate and the layer roughness are determined.NanoÅ”enje elektriÄnom iskrom postupak je za navarivanje tvrdih metalnih slitina, npr. karbida i stelita, na povrÅ”inu novih ili starih elemenata strojeva. U tom postupku visoka struja provodi se kroz oscilirajuÄu elektrodu i supstrat na vrlo kratko vrijeme. U Älanku opisan je postupak i odreÄeni su debljina nanesenog sloja, kemijski sastav, stupanj mijeÅ”anja i hrapavost sloja
Izrada dvoplastnog alata za ubrizgavanje termoplasta postupkom zavarivanja
The article presents the technology of deposit cladding different materials, using the injection molds for thermoplastic as a case study. The aim of the study is to surface weld to the working surface of the mold a different material with corresponding physical properties. Steel (1.1141) and a copper alloy were used as the base, onto which different materials were surface-welded. Tungsten inert gas (TIG) welding was employed to make molds inserts. An analysis of cross-sectioned specimens was made by optical microscopy, and chemical and hardness profiles were measured too. The thermal conductivity of base and cladded layer was also tested. Finally, a thermal fatigue test was employed to investigate the thermal fatigue properties of such surfaces.U Älanku predstavljena je tehnologija navarivanja razliÄitih materijala na primjeru alata za ubrizgavanje termoplasta. Cilj istraživanja je navarivanje drukÄijeg materijala s odgovarajuÄim fizikalnim svojstvima na radnu povrÅ”inu alata. UloÅ”ci alata izraÄeni su postupkom zavarivanja volframovom elektrodom uz zaÅ”titu inertnog plina (TIG). Kao osnova na koju su navareni razliÄiti materijali koriÅ”teni su Äelik (1.1141) i bakarna slitina. PopreÄni presjek uzoraka analiziran je optiÄkim mikroskopom, izmjereni su i kemijski profil i profil tvrdoÄe. Testirana je i toplinska provodljivost osnovnog i navarenog materijala. Na kraju je izvrÅ”en i test termiÄkog zamora u svrhu istraživanja svojstava termiÄkog zamora takvih povrÅ”ina
Computing the common zeros of two bivariate functions via BĆ©zout resultants
The common zeros of two bivariate functions can be computed by finding the common zeros of their polynomial interpolants expressed in a tensor Chebyshev basis. From here we develop a bivariate rootfinding algorithm based on the hidden variable resultant method and BĆ©zout matrices with polynomial entries. Using techniques including domain subdivision, BĆ©zoutian regularization, and local refinement we are able to reliably and accurately compute the simple common zeros of two smooth functions with polynomial interpolants of very high degree (ā„ 1000). We analyze the resultant method and its conditioning by noting that the BĆ©zout matrices are matrix polynomials. Two implementations are available: one on the Matlab Central File Exchange and another in the roots command in Chebfun2 that is adapted to suit Chebfunās methodology
The manufactoring of a twoālayered injection mold by welding
The article presents the technology of deposit cladding different materials, using the injection molds for thermoplastic as a case study. The aim of the study is to surface weld to the working surface of the mold a different material with corresponding physical properties. Steel (1.1141) and a copper alloy were used as the base, onto which different materials were surface-welded. Tungsten inert gas (TIG) welding was employed to make molds inserts. An analysis of cross-sectioned specimens was made by optical microscopy, and chemical and hardness profiles were measured too. The thermal conductivity of base and cladded layer was also tested. Finally, a thermal fatigue test was employed to investigate the thermal fatigue properties of such surfaces