Analysis of Nanoprecipitation Effect on Toughness Behavior in Warm Worked AA7050 Alloy

Commonly adopted main methods aimed to improve the strength–toughness combination of high strength aluminum alloys are based on a standard process. Such a process includes alloy solution heat treatment, water-quench and reheating at controlled temperature for ageing holding times. Some alloys request an intermediate cold working hardening step before ageing for an optimum strength result. Recently a warm working step has been proposed and applied. This replaces the cold working after solution treatment and quenching and before the final ageing treatment. Such an alternative process proved to be very effective in improving strength–toughness behavior of 7XXX aluminum alloys. In this paper the precipitation state following this promising process is analyzed and compared to that of the standard route. The results put in evidence the differences in nanoprecipitation densities that are claimed to be responsible for strength and toughness improved properties.

The Effect of annealing temperature on corrosion resistance and microstructure of Zr-Sn-Nb-Fe alloy

The Ti-2Al-2.5Zr titanium alloy plate in beta phase water quench at different times of the reentry after annealing is implemented while primary phase number and size distribution of samples are obtained. This research is carried out on corrosion behavior in 3.5% [mass fraction] NaCl solution. Experimental study showed that after the beta phase water quenching Ti-2Al-2.5Zr titanium alloyed after 500 oC annealing when partial recrystallization happened. There seems to be lots of tiny dispersion in the alloy that was annealed with its samples of six-party [HCP] structure of Ti, Zr, Al phase 2 with the dimension below 100 nm. Reaching 500 oC when the rate of annealing at a primary phase of the sample at 550 oC is low 90% of the primary phase is less than 100 nm. The changing of the rule of present decreasing also triggers little difference overall. Precipitation in the process of annealing Zr [Nb,Fe,Cr] 2is less that proves to be good for corrosion resistance.

Numerical Simulation of Heat Treatment Process of Aluminium Profiles

The paper deals with the simulation of cooling processes of the aluminium profiles inside the water quench. Cooling of profile surfaces is performed by water spray, which is created by mixing a water and an air in a nozzles. Formulas were found in literature, modified and applied to a given problem that significantly simplified a solution. The task of numerical simulations was to determine temperature and velocity profile on aluminium profile surfaces for establishing of the heat transfer coefficient which was used as the convective boundary condition necessary to solve the heat transfer in the aluminium profile by finite element method. The difference between FEM and CFD results is up to 10%.

Study of Opto-Mechanical Properties of Tubular Water Quenched Polyethylene Films

Tubular Water Quench (TWQ) is commonly used process to make Polypropylene based films (TQPP). This process has been tried for the first time to make Polyethylene films (TQPE) from HDPE-LLDPE blend. Polyethylene inculcates the inherent materialistic property of softness and better feel to the film. The key requirement for TWQ films are Openability and transparency. This paper focuses on novel developmental work done, using Polyethylene blend for making TQPE film, comparing it’s optical and mechanical properties with TQPP films.

Thermal shock properties of glass-ceramics synthesized from a glass frit

In this study, the behavior of glass-ceramics synthesized from a glass frit of FFW (Final Flotation Waste) originated from the RTB Bor Company was investigated. Thermal shock resistance was monitored in order to assess the possibility of application of such waste material. Thermal shock of the samples was conducted using water quench test. Image analysis and ultrasonic measurements were used as nondestructive methods for quantification of thermal shock damage at the surface and in the bulk of the specimens. Phase composition of samples was determined by X-ray powder diffraction (XRPD). The degradation level of samples was about 43 % after 20 cycles of water quench tests. The results pointed out that glass-ceramic material exhibited good thermal shock resistance.