Analysis of process parameter variations and heat treatment effects on the microstructure and mechanical properties of Inconel 718 fabricated by laser powder directed energy deposition (LP-DED)

Effect of heat treatments on the microstructure and mechanical properties of an ultra-high strength martensitic steel fabricated via laser powder bed fusion additive manufacturing

Microstructure and mechanical properties of laser DED produced crack-free Al 7075 alloy: Effect of process parameters and heat treatment

Effects of additive manufacturing process parameters and heat treatment on texture evolution and variant selection during austenite-martensite transformation in 18%Ni-M350 maraging steel

Joining dissimilar materials as coatings or multimaterial compounds remains challenging due to mismatches in atomic orientation, microstructure, and thermal properties. The laser powder directed energy deposition (LP‐DED) process is an additive manufacturing (AM) technique capable of producing bimetallic or functionally graded materials for coatings or heavy‐duty applications. However, understanding interface characteristics in response to process parameters and heat treatment is critical for evaluating structural integrity. This study investigates the Inconel 718/CuCrZr interface and examines the effects of process parameters and heat treatment on microstructural evolution. The optimized bimetallic sample is free of cracks and excessive porosity, indicating a successful deposition. The results show that Inconel 718 acts as a thermal barrier during CuCrZr deposition due to its low thermal conductivity, significantly influencing grain structure and hardness. To achieve a homogeneous interface, four heat treatment strategies are used, and their effects on microstructure and hardness are analyzed. These strategies induce major changes in joint properties, demonstrating that an appropriate heat treatment improves hardness, interface characteristics, and microstructural uniformity. The findings confirm that achieving the desired interface properties for coatings or multimaterial production is possible through optimized process parameters and heat treatment.

Effect of heat input and post-weld heat treatment on surface, texture, microstructure, and mechanical properties of dissimilar laser beam welded AISI 2507 super duplex to AISI 904L super austenitic stainless steels

Effect of heat treatment on the microstructure and mechanical properties of blended elemental Ti–6Al–4V produced by powder forging

Improved corrosion resistance and mechanical properties of biodegradable Mg–4Zn–xSr alloys: effects of heat treatment, Sr additions, and multi-directional forging

The effect of different heat treatments on microstructure and mechanical property of 30Si2MnCrMoV steel weld specimen was studied in this paper．A stress relieving annealing on the specimen was carried out immediately after welding. And then two heat treatments were carried out on the specimen. Observation results showed that the original microstructure of 30Si2MnCrMoV welded joints was granular pearlite and the microstructure of weld bead was coarse martensite. Lots of tempered martensite exited in the weld specimen under quenching-tempering heat treatment, the carbide was coarse and the content of retained austenite was little. Under Quenching and Partitioning (Q&P) heat treatment, the content of retained austenite increased to 7% and a small number of coarse carbides existed. The determination of mechanical properties showed that, comparing with quenching-tempering process, the plasticity and toughness of weld specimen treated by Q&P was enhanced significantly, the percentage elongation increased 30%, the impact energy increased 25% ,the intensity reduced little and comprehensive mechanical property was excellent. The tensile fracture of 30Si2MnCrMoV steel under Q&P presented dimples. The retained austenite which exited along the lath boundaries of lath martensite was the main reason of the reduction of secondary cracks and the improvement of plasticity and toughness.

Effects of heat treatments on microstructure and mechanical properties of laser melting multi-layer materials

Purpose This study aims to apply solution heat treatment (SHT) to AlSi10Mg material produced by laser powder bed fusion (LPBF) technique at lower temperatures and times instead of the conventional T6 heat treatment (540°C/2 h). Design/methodology/approach The effects of these heat treatments on the microstructure, phase transformation and corrosion properties of the material were investigated. Optical microscope, Smartzoom5 device (with Zen Core 3.5 program), scanning electron microscopy (SEM), focused ion beam SEM (FIB-SEM) and Energy dispersive X-ray analysis techniques were used to examine the microstructural properties, and X-ray diffractometry (XRD) techniques were used to determine the phase analysis. Potentiodynamic polarization and electrochemical impedance spectroscopy techniques were used for corrosion measurements. Findings The results were compared with conventional T6 heat treatments, revealing that the developed alternative dissolution heat treatments showed better corrosion resistance than the traditional T6 heat treatment. Originality/value This study presents a new alternative to the traditional T6 heat treatment with SHT, which is performed over a long time and temperature, and a new alternative to heat treatment at a shorter time and temperature. These findings are of significant industrial importance because AlSi10Mg alloys are used in critical areas today.

A supermartensitic stainless steel with composition 12.2%Cr-5.8%Ni-1.90%Mo-0.028%C (%wt.) was welded by gas tungsten arc welding (GTAW) with superduplex stainless steel filler metal. Post weld heat treatments (PWHT) at 650 ºC for different periods of time were performed in order to decrease the hardness in the heat affected zone (HAZ). This paper deals with the effect of these heat treatments on the microstructure and mechanical properties of the joint. Mechanical strength of the weld joint was slightly inferior to the base metal, but was not affected by heat treatments. Precipitation of intermetallic phases in the weld metal (WM) due to prolonged PWHT was detected by scanning electron microscopy. The impact toughness of the weld metal decreased with the increase of time of heat treatment, due to intermetallic precipitation. However, even in the specimen treated for 1h, the Charpy energy remained above 27J at -46 ºC. It was found that optimum mechanical properties can be obtained with heat treatment for 30 minutes at 650 ºC.

Effect of heat treatment on the microstructure and mechanical properties of Ti6Al4V gradient structures manufactured by selective laser melting

Evolution of microstructure and mechanical properties of Al-5 wt% Ti composite fabricated by P/M and hot extrusion: Effect of heat treatment

Newborn ruminants depend on colostrum intake immediately after birth to obtain immunoglobulins for effective transfer of passive immunity (TPI). As colostrum may also be a vehicle of infectious agents, heat treatment of raw colostrum is a practice aimed at eliminating or reducing its pathogen load. Despite the usefulness of heat treatment in preventing the transmission of infectious colostrum-borne diseases, heat treatment of colostrum may have some side effects. A systematic review and meta-analysis were conducted to summarize the effects of colostrum heat treatment on colostral viscosity and IgG concentration, and serum IgG concentration as a proxy for TPI in newborn calves fed raw versus heat-treated colostrum. Moderators were studied to identify sources of heterogeneity. Literature databases were searched for peer-reviewed articles published between 1946 and 2022. A Master of Science thesis was also included. Five, 21, and 19 original publications were quantitatively evaluated in 3 separate meta-analyses, based on predefined selection criteria. Two-level and 3-level random-effects meta-analysis revealed a significant overall effect of heat treatment on colostral viscosity and IgG concentration, and serum IgG concentration in newborns. Heat-treated colostrum had significantly higher viscosity (21.0 cP, 95% CI: 3.8 to 38.2) and lower IgG concentration (-7.4 g/L, 95% CI: -11.1 to -3.7) compared with raw colostrum. Overall, newborn calves fed heat-treated colostrum had higher serum IgG concentrations (2.8 g/L, 95% CI: 1.4 to 4.0) 24-48 h after birth than those fed with raw colostrum. Particularly, this positive effect on the serum IgG concentrations was seen when colostrum was heat-treated at ≤60°C (2.9 g/L, 95% CI: 0.9 to 4.2) and when the standard low-temperature low-time (LTLT) method was used for heat treatment (2.6 g/L, 95% CI: 0.1 to 5.1). Colostrum treated at >60-63.5°C tended to have higher viscosity (275.6 cP, 95% CI: -37.9 to 589.3) and had lower IgG concentration (-21.7 g/L, 95% CI: -27.3 to -16.1). Calves fed colostrum treated at this temperature range had significantly lower serum IgG (-4.2 g/L, 95% CI: -7.9 to -0.4) compared with those fed raw colostrum. Heat treatment of colostrum at 72-76°C was not associated with a significant increase in colostral viscosity (6.3 cP, 95% CI: -324.3 to 336.9) nor a reduction in IgG colostral concentration (-13.1 g/L, 95% CI: -26.5 to 0.2), but calves fed colostrum treated at this temperature range had a significant reduction in serum IgG (-11.3 g/L, 95% CI: -17.1 to -5.4). Feeding newborn calves with colostrum heat-treated at ≤60°C by the standard LTLT method, particularly within 2 h after birth, resulted in increased serum IgG concentration at 24-48 h of age. Importantly, delaying feeding of heat-treated colostrum to newborns beyond 2 h of age resulted in no significant difference in IgG serum levels compared with feeding raw colostrum, highlighting the importance of early administration of heat-treated colostrum to favor TPI. On-farm colostrum heat treating should achieve an equilibrium between pathogen elimination and the preservation of colostral immunoglobulins while minimizing undesired increases in viscosity. The beneficial effects of colostrum heat treatment on TPI can be negligible if colostrum feeding is not performed within 2 h after birth.

Effect of heat treatment and in vitro aging on the microstructure and mechanical properties of cold isostatic-pressed zirconia ceramics for dental restorations