The present paper reports the results of theoretical and experimental studies of the process of die forging a bimetallic door handle intended for the production of a helicopter. The aim of the studies was to develop and implement a technology for die forging of a product with a specific mass similar to that of magnesium alloys which will have, however higher corrosion resistance. Numerical modelling and industrial tests were carried out based on the previously forging processes for an AZ31 alloy door handle. The material for the tests was a bimetallic bar produced by the explosive welding method, in which the core was of alloy AZ31, and the cladding layer was made of 1050A grade aluminium. The studies were conducted for two variants: Variant I – the forging process was mapped by numerical modelling and industrial tests for the die shape and parameters used in the forging of the AZ31 alloy door handle, Variant II – the tool shape was optimized and process parameters were selected so as to obtain a finished product characterized by a continuous Al layer.

From the theoretical studies and experimental tests carried out it has been found that the application of the Variant I does not assure that a finished door handle characterized by a continuous cladding layer will be produced. Within this study, a novel method of bimetallic door handle die forging (Variant II) has been developed, which limits the amount of the flash formed and assures the integrity of the cladding layer.

The aim of the study was to determine the influence of posttraumatic enophthalmos in orbital blow-out fracture on the treatment results. The relationship between time from injury to treatment, type of surgical reconstruction, bone graft site, type of diplopia and treatment results were evaluated. The relationship between the location of the fracture and the degree of enophthalmos was also analyzed. The study included 730 patients, 128 women and 602 men, aged 4 to 77 years, average 28 years, treated because of orbital blow-out fracture in our Department between 1975 and 2015. The study included only patients with an isolated orbital floor or medial wall fracture, so-called „pure blow-out” or „internal blowout”. Fractures of the lower rim, roof or lateral wall of the orbit, as well as the coexistence of other fractures of the facial part of the skull, were excluding citeria from the study. Complete recovery in surgically treated patients was achieved in 405 (58.8%) patients, improvement in 179 (26%) and no improvement in 105 (15.2%) patients. The degree of post-traumatic enophthalmos affects the result of the treatment. The location of the orbital fracture affects the enophthalmos, in our group of patients the largest incidence occurred in the fracture located in the orbital floor combined with medial wall. Patients who underwent surgical treatment up to 14 days after the injury achieved better results than those postponed.