Multiattribute Assessment of Consumables for TIG Welding of Aluminum Alloys

Table 3

List of attributes and alternates for shielding gas [7, 8].

Properties	Pure argon	Pure helium	25% argon + 75% helium	75% argon + 25% helium	50% argon + 50% helium
(1) Thermal conductivity	0.016	0.1513	0.1174	0.0498	0.0836
W/mK at (1.013 bar at 0°C)
(2) Gas density (lb/wft) at 0°C, 1 atm	0.1114	0.0111	0.0361	0.0863	0.0612
(3) Specific gravity (g/cm^3) air = l	1.38	0.1368	0.4476	1.0692	0.7584
(4) Ionization potential (eV)	15.7	24.5	22.3	17.9	20.1
(5) Cost (per 100 g) ($)	0.5	5.2	4.025	1.675	4.15
(6) Specific heat capacity at	0.520	5.19	4.0225	1.6875	2.855
kJ/Kg·K Cp (1.013 bar and 25°C)