Age-hardening characteristics in a dental low-gold alloy composed of 40.0 wt% Au-35.0 wt% Ag-7.9 wt% Pd-7.0 wt% Cu-5.0 wt% In-3.5 wt% Zn-1.5 wt% Sn, were investigated by means of the hardness test, XRD study, SEM observations and EPMA. The following results were obtained. The age-hardening was characterized by a precipitation of Cu-rich alpha2 phase in the a phase. The softening that occurred f...

The influences of age hardening and HIP (Hot Isostatic Pressing) on the mechanical properties of A356 (Al 7Si 0.6 Mg) casting alloys were studied. Cast bars were homogenized, heated and maintained at a temperature of 540°C for a duration of 2 hours, followed by rapid cooling in a polymeric solution. The castings were age hardened at 180°C for a duration of 4 hours before being subjected to HIP ...

In the present study, multi-objective optimization is employed to develop optimum heat treatments that can achieve both high-mechanical performance and non-distinctive crystallographic texture of 3D printed Inconel 718 (IN718) fabricated by laser powder bed fusion (LPBF). Heat including homogenization at different soaking times (2, 2.5, 3, 3.5 4 h) 1080 °C, followed a 1 h solution treatment 980...

aqueous polymer quenchants are being used increasingly in steel heat treatment industries as a substitution for conventional quenchants. by adjusting the quench parameters of the polymeric media, it is possible to achieve desirable microstructure and mechanical properties in addition to reduction in distortion and cracking. in this work, polyalkylene glycol (pag) aqueous solution was used as th...

Plane strain transient finite thermomechanical deformations of heat-conducting functionally gradient materials comprised of tungsten and nickel–iron matrix are analyzed to delineate brittle/ductile failures by the nodal release technique. Each material is modeled as strain-hardening, strain-rate-hardening and thermally-softening. Effective properties are derived by the rule of mixtures. At nomi...

in this study, attempts were made to recovery the used turbine blades made up of inconel738 by electro slag remelting (esr) method. using an appropriate slag and addition of metallic aluminum, the original composition was maintained and the amount of oxygen, hydrogen and nitrogen remained in the acceptable level. in order to explore the effect of remelting with esr on the microstructure, tensil...

the effect of ferrite grain size on the fatigue and tensile properties of dual phase steels with a 0.25 volumefraction of martensite (vm) under different heat treatments was investigated. the heat treatments werehomogenized at 1200 oc along with several subsequent normalizations at 910 oc, resulting in differentmicrostructures and mechanical properties. after heat treatment, the obtained steels...

despite having some useful properties, stainless steels suffer from lack of suitable surface hardness. in this research electroless ni-b-tl coating was used with the aim to increase their surface hardness. the effects of nickel chloride, sodium borohydride, thallium nitrate and ethylendiamin on the chemical composition of coating were studied. to achieve an increase in hardness, the effects of ...

The present work reflects the effects of trace addition copper (up to 1 wt.%) and zinc (0.5 on microstructure hardness property heat treated A356 (Al-7Si) alloy. Small amount was introduced into in both atomic form (alloy) powder (composite) its age hardening behaviour were investigated. To enhance wettability during composite fabrication solid solution strengthening alloys, a small quantity ma...

Steel containing 0.03% carbon, 1.35% copper and 0.84% nickel had yield strength in the 540-625 MPa (78-90 Ksi) range depending on thickness, ultimate tensile strength in the 625-690 MPa (90100 Ksi) range, and 25-30% elongation when air cooled after hot rolling. No brittle heat-affected zone was formed during manual or automatic submerged arc welding without pre-heating or postheating. The fract...