W. Pakieła

Surface Layer Properties of Sintered Ferritic Stainless Steel Remelted and Alloyed with FeNi and Ni by HPDL Laser

Laser surface remelting and alloying of sintered stainless steel type 410L with FeNi and Ni have been studied for improvement of corrosion resistance and hardness increase. The influences of high power diode laser (HPDL) processing conditions, laser power in range 0.7-2.1 kW on the microstructure and properties of alloyed surface layer have been evaluated. The FeNi alloyed layer shows microstructure composed of austenite and martensite formed, due to high cooling rate in laser remelting process, with average Ni content in range of 39 to 8% depending on laser processing conditions. The Ni alloyed layer was composed of austenitic microstructure with Ni content from 65% to 33%. The improvement in microhardness was achieved by laser surface alloying and remelting. Excellent corrosion properties were observed for such remelted and alloyed layers in salt spray test.

Shaping of Surface Layer Structure and Mechanical Properties After Laser Treatment of Aluminium Alloys

The influence of laser treatment on the structure, mechanical properties and wear resistant casting of aluminium alloys has been studied. The main objective of this investigation was to improve the tribological and mechanical properties of the surface layer of the aluminium alloy AlMg5Si2Mn by remelting and feeding the chromium particles into the melt pool with a rapid solidification. The applied size of the chromium particles have been in the range 50–120 μm. For the remelting of the surface a high power diode laser (HPDL) was used. The applied laser beam power is in the range from 1.8 to 2.2 kW. The linear laser scan rate of the beam was set to 0.5 m/min. The chromium powder has been introduced in the melt pool using a gravity feeder at a constant rate of 2 g/min. The application of the laser surface treatment of aluminum alloys enables us to obtain too much harder and better wear resistance compared to based materials.

Evaluation of Functional Properties of the Rapidly Solidified Cast AlSi30 Alloy as a Material for Transport Applications

The AlSi30 alloy obtained by melt spinning in the Rapid Solidification process, after fragmentation and consolidation, was subjected to plastic forming. As a result, extrusions in the form of 18 mm rods were obtained, and after forging and heat treatment (T6) were tested for selected functional properties. Mechanical properties, corrosion resistance and tribological properties were determined. Finally, a material with unconventional chemical composition was obtained, which confirmed its applicability for, among others, components operating in the transport industry, mainly pistons.