La2O3-reinforced W and W–V alloys produced by hot isostatic pressing

Abstract

W and W V alloys reinforced with La 2 O 3 particles have been produced by MA and subsequent HIP at 1573 K and 195 MPa. The microstructure of the consolidated alloys has been characterized by scanning electron microscopy, energy dispersive spectroscopy analyses and X ray diffraction. The mechanical properties were studied by nanoindentation measurements. The results show that practically full dense billets of W V, W V La 2 O 3 and W La 2 O 3 alloys can be produced. The microstructure analysis has shown that islands of V are present in W V and W V 1La 2 O 3 alloys. In W 1La 2 O 3 islands of La 2 O 3 are also pres ent. The nanohardness of the W matrix increases with the addition of V, while decreases with the addi tion of La 2 O 3 .

SANS evidence for the dispersion of nanoparticles in W–1Y2O3 and W–1La2O3 processed by hot isostatic pressing

“…Nevertheless, the DBTT and RCT for W can be improved by addition of some dopants. Recently, W 1Y 2 O 3 and W 1La 2 O 3 alloys have been produced by mechanical alloy ing and subsequent consolidation by hot isostatic pressing [4,5]. The improvement of the high temperature mechanical properties of the oxide dispersion strengthened (ODS) W alloys would be associated with the fine dispersion of the oxide nano particles, which can inhibit the dislocation motion and grain growth.…”

Microstructure and temperature dependence of the microhardness of W–4V–1La2O3 and W–4Ti–1La2O3

“…The average crystallite size and cumulative microstrain estimated from the width of the XRD peaks were: 129.6 nm and 0.39% for 10 h milled W-4VLa, 29.0 nm and 0.56% for 20 h milled W-4TiLa, and 26.8 nm and 0.90% for 30 h milled W-4TiLa. The O excess in the milled powder rose significantly increasing the milling time from 10 to 30 h. SEM analyses revealed that the HIP treatment produced the segregation of some V or Ti into large pools of these elements sparsely distributed in the corresponding alloy [6,7]. Fig.…”

“…Oxide reinforcement, or Al-K-Si doping, can enhance the mechanical strength of W and increase its recrystallization temperature, although without lowering the DBTT [3,4]. Recently, W-Ti and W-V alloys, reinforced or oxide dispersion strengthened (ODS) with Y 2 O 3 or La 2 O 3 , have been produced by mechanical alloying and subsequent consolidation by hot isostatic pressing (HIP) [5][6][7]. It has been reported that the addition of Ti by itself, or combined with Y 2 O 3 , can moderately enhance the strength and fracture toughness of W in the temperature range below 873 or 1073 K, and noticeably enhance microhardness [8,9].…”

Thermal stability of the grain structure in the W-2V and W-2V-0.5Y2O3 alloys produced by hot isostatic pressing

“…W-2V and ODS W-2V-0.5Y 2 O 3 (wt%) alloys, hereafter referred to as W2V and W2V0.5Y, were produced following a powder metallurgy route consisting of mechanical alloying and subsequent high isostatic pressing (HIP) for 2 h at 1573 K and 200 MPa, following the procedure described elsewhere [8].…”