Tools get failured during work; wear is a major factor that contributes to failures. Damaged tools are replaced or filed. This investigation describes typical changes that occur in the heat affected zone of tool (HAZ), which was repaired by surfacing with a TIG and with micro-plasma procedure. Microstructure of the steel on the repaired tool was analysed by an optical and scanning electron microscope. The discussed tool was made of chromium ledeburitic steel type W.N. 1.2379 and it was repaired by surfacing steel type W.N. 1.4718. Changes in the HAZ also depend on the type of surfacing.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 994399For economical production of cold formed steel forgings for the automotive industry it is important that they have a long working life. During their exploitation they are exposed to the high mechanical and temperature loads. Their corresponding properties are achieved by a heat treatment process. As example is presented an optimisation of heat treatment procedure for typical steel forging (pinion). Result of the used heat treatment are steel pinions with the surface hardness of approx. 65 HRC, and case hardened depth of the surface layer with hardness higher than 551 HV1 approx. 0.7 mm.
F.04 Increase of the technological level
COBISS.SI-ID: 970591Investigation deals with superplastic properties of an Al-4Mg-0.6Mn alloy (AA5083) with 0.3wt. % of added Sc. Investigated alloy was produced by ingot casting and thermomechanically treated with hot and cold rolling into a sheet with a thickness of 1.4 mm. Superplastic properties of the alloy were investigated in tensile tests at strain rates in range 3x10-4 to 1x10-2s-1 and at T = 470 to 570°C. We examined the true stress, true strain, elongation to failure, strain-rate sensitivity index and microstructure of the alloy. Elongation to failure increased with test temperature and was over 1400%.
F.06 Development of a new product
COBISS.SI-ID: 778410In this study we report on the synthesis of a gadolinium-based magneto-caloric alloy using the technique of arc melting. This alloy belongs to the group of metallic materials that exhibit a considerable magneto-caloric effect, and which have the potential to be used for a range of refrigeration applications. A series of five alloys weighing from 1 g to 5 g with the nominal composition Gd5Ge2Si2 were prepared and examined using optical (LOM) and electron microscopy (SEM with EDS) and XRD in the as-cast and heat-treated conditions.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 909919Presented work discusses a complex process of inductive heating and quenching of carbon steel planetary shafts for diesel engine starters. Intensity and homogeneity of temperature fields on the surface of the planetary shafts were measured by thermographic camera. On the measurements base and theoretical knowledge, a mathematical model for temperature conditions determination in the shaft during the entire process of heating and quenching was carried out. On the basis of developed mathematical model a computer program was done, and used for analyses and process optimization.
F.14 Improvements to existing production methods and tools or processes
COBISS.SI-ID: 10971675