State primary standard of units of specific adsorption of gases, specific surface area, specific pore volume, pore size, open porosity and gas permeability coefficient of solids and materials GET 210-2019

Methods and instruments the characteristics of porosity and permeability of solids and materials are described, which are part of the improved GET 210-2014. The metrological characteristics of the GET 210-2014 are compared and after its improvement the GET 210-2019. Certified reference materials of approved types based on micro-, meso- and macroporous solids are considered. The results of international comparisons, confirmed measuring and calibration capabilities, as well as a comparison of the metrological characteristics of the GET 210-2019 with the standards of foreign countries are presented.

Effect of filler wire properties on porosity formation in laser welding of AC-170PX aluminium alloy for lightweight automotive component manufacture

AC-170PX (AA6014) alloys are typically used in lightweight automobile vehicles. Laser welding can be a viable tool for the assembly of components. However, porosity is often generated during aluminium welding. In this article, an investigation is reported on the characteristics of porosity formation in high-power disc laser welding of AC-170PX aluminium alloy sheets in two weld joint configurations: fillet edge and flange couch with three different filler wires of 4xxx, 3xxx and 5xxx aluminium series for each joint. Porosity, microstructures, tensile strengths and joint geometry were investigated. It has been found that the use of filler wires with higher Mg and Mn content such as AA5083 and AA3004 leads to a significant reduction in porosity to less than 1.5% in both types of joints compared with up to 80% porosity with the silicon-rich AA4043 wire. The mechanism that led to this improvement is discussed.

Understanding the Effect of Heat Input and Sheet Gap on Porosity Formation in Fillet Edge and Flange Couch Laser Welding of AC-170PX Aluminum Alloy for Automotive Component Manufacture

An investigation is reported on the characteristics of porosity formation in high power disk laser welding of AC-170PX (AA6014) alloy sheets (coated with titanium and zirconium) in two weld joint configurations: fillet edge and flange couch with AA4043 filler wire for potential automotive manufacturing applications. Porosity, macro- and microstructure characteristics, tensile strengths, microhardness, and joint geometry were investigated. It has been found that an increase in heat input and welding speed generates more porosity in both types of joints. The introduction of a 0.2 mm gap reduces porosity significantly in the fillet edge joints but it does not have noticeable effect on the flange couch joints. The mechanism of the porosity formation is discussed.