Evaluation of 5-axis HSC dynamic behavior when milling TiAl6V4 blades

Abstract

Gas combustion represents the second principal way of electricity generation due to its

Joining of Dissimilar Alloys Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo-0.1Si Using Linear Friction Welding

“…Bladed integrated disks (Blisks)—manufactured by machining a single forged billet into a monolithic blade-disk assembly—were introduced in aero-engines as an advanced alternative [ 1 ] to mechanical fastening/joining of blades to disks via a fir-tree arrangement that faced service life limitations and failures due to fretting fatigue damage at the contact surfaces between the blade dovetail root and the disk slot [ 2 ]. Though the blisk technology demonstrated significant gains in weight reduction, aerodynamic performance, space reduction, product quality and service life, the monolithic manufacturing approach has encountered significant machining challenges [ 3 ], especially for blisks with high blade lengths in the low-pressure compressor stages. More importantly, however, has been the impossibility of mechanical performance tailoring in the monolithic blisk design through dissimilar alloy selection and microstructural modification for the specific operational conditions on the blades (exposed to high cycle fatigue and higher temperatures) relative to the disk (exposed to low cycle fatigue) [ 3 ].…”

“…Though the blisk technology demonstrated significant gains in weight reduction, aerodynamic performance, space reduction, product quality and service life, the monolithic manufacturing approach has encountered significant machining challenges [ 3 ], especially for blisks with high blade lengths in the low-pressure compressor stages. More importantly, however, has been the impossibility of mechanical performance tailoring in the monolithic blisk design through dissimilar alloy selection and microstructural modification for the specific operational conditions on the blades (exposed to high cycle fatigue and higher temperatures) relative to the disk (exposed to low cycle fatigue) [ 3 ]. This has led to avid research and development in the aerospace field over the past two decades on suitable joining technologies for titanium alloys [ 4 , 5 , 6 , 7 , 8 , 9 ], and in particular their solid-state assembly by linear friction welding (LFW) [ 10 , 11 , 12 ] that has now been qualified for aero-engine blisk manufacturing because the welds exhibit high integrity (free from defects such as porosity or inclusions), fine-grain “forged” microstructures in the central weld zone (CWZ) with limited thermomechanically affected zones (TMAZs) and heat affected zones (HAZs), as well as high joint efficiencies—ratio of the strength of the joint compared to the parent material (PM).…”