T6 Heat Treatment Conditions Research Articles

On the mean stress sensitivity of cast aluminium considering imperfections

The mean stress sensitivity of an imperfective and a near-defect free aluminium cast alloy is analysed in this work. Thereby, metallographical, quasi-static, high cycle fatigue and crack propagation investigations are conducted. The specimens are taken out from an Al–Si–Cu sand cast component with either T6 heat treatment or hot isostatic pressing (HIP) condition. As the specimens are extracted from similar positions, technological size effects in terms of varying microstructural properties, such as the dendrite arm spacing and micro pore size distribution, are suppressed. The crack propagation tests enable the build up of load stress ratio dependent crack growth resistance curves, revealing no significant change of crack closure mechanisms between T6 and HIP condition. But the load stress ratio shows a significant impact on the contributions of crack closure mechanisms to the long crack threshold. The experimental data indicates that common mean stress sensitivity models can lead to non-conservative fatigue design.Finally, a mean stress sensitivity model for fatigue strength assessment is set up, merging existing approaches of the linear elastic fracture mechanics and nominal stress fatigue assessment methods to a three dimensional fatigue assessment map. The introduced approach takes both the present critical defect size for a given probability of occurrence, as well as the decreasing fatigue strength and diminishing contributions of crack closure effects with increasing load stress ratio R into account. The model is validated by for HIP and T6 post-treated material under alternating and tumescent test conditions, revealing an average deviation of only three percent to the experimental data.

Response of Varying Levels of Silicon and Transition Elements on Room- and Elevated-Temperature Tensile Properties in an Al–Cu Alloy

The research involved here was accomplished through a study of the tensile properties in both the as-cast and heat-treated conditions, where the effects of different heat treatments, i.e., T5, T6, T62 and T7, commonly applied to aluminum casting alloys were evaluated at ambient temperature and at high temperature (250 °C) using different holding or stabilization times at testing temperature. The tensile data showed that the ultimate tensile strength (UTS) and percentage elongation values of the six alloys increased in the one-step solution heat-treated condition compared to the as-cast case. The multi-step solution heat treatment displayed higher tensile properties than those achieved with the one-step solution treatment. The use of the T62 treatment (multi-step solution treatment followed by artificial aging) allows for maximum dissolution of the copper phases in the multiple stages of solution treatment, resulting in the greatest improvement in both UTS and yield strength (YS). At ambient temperature, T6 and T62 treatments provide the best improvements in both UTS and YS values of all alloys. The T62-tempered alloy showed maximum improvement with a UTS value of ~ 401.55 MPa. Likewise, in the Al–2%Cu–8%Si series the T62-tempered alloy displayed the highest UTS with a value of ~ 293.5 MPa. The YS values improved overall after solution treatment. The YS values followed the same trend as the UTS at both ambient and high-temperature testing. At high-temperature testing at 250 °C after one hour of stabilization, the UTS of the alloys increased with the T6 and T62 heat treatment conditions, but remained the same after T5 heat treatment; the highest UTS value was exhibited by the T62-tempered alloy with ~ 195 MPa.

Synthesis and characterization of graphene nanoplatelets reinforced AA7068 matrix nanocomposites produced by liquid metallurgy route

In this paper, we report the synthesis of graphene nanoplatelets (GNPs) reinforced AA7068 metal matrix nanocomposites by a combination of ultrasonication, powder and liquid metallurgy techniques. The effect of GNPs with a varying weight fraction (0.1, 0.3, 0.5, 0.7 and 1wt%) on microstructure, mechanical and tribological properties of AA7068 metal matrix is studied. In addition to this the developed nanocomposites were subjected to the standard T6 heat treatment conditions and its effect on aforementioned properties was also studied. Mechanical properties of as cast and T6 heat treated nanocomposites showed increase in tensile strength and elongation values up to 0.5wt% GNPs reinforced AA7068 nanocomposites, thereafter drop in these properties was observed. A similar behavior was observed in case of grain size, where grain refinement of AA7068 matrix by GNPs reached saturation point for 0.5wt%. The average ultimate tensile strength (UTS) of the specimens before and after extrusion processes and T6 heat treatment increases from 263MPa to 372MPa and 495–615MPa after adding 0.5wt% GNPs, respectively. Finally, the wear resistance of the AA7068 alloy and its nanocomposite with 0.5wt% GNPs in T6 conditions was significantly higher than that of as cast conditions. The obtained results indicate that GNPs (up to 0.5wt%) are effective in improving the mechanical properties and wear resistance of AA7068 metal matrix in both as cast and T6 conditions.

Optimization of heat treatment of gravity cast Sr-modified B356 aluminum alloy

Abstract In recent years, certain foundry processes have made it possible to obtain products with very thin parts, below the 4 mm threshold of the permanent mold casting technology. The safety margins of these castings have been reduced, so the T6 heat treatment conditions adopted for the Al–7Si–Mg alloys need to be investigated to identify the best combination of strength and ductility. Furthermore, the cost and the production time associated with T6 heat treatment have to be optimized. In the present work, an experimental study was carried out to optimize the solution treatment and artificial aging conditions in gravity cast thin bars of B356 aluminum alloy modified with Sr. Two solution temperatures were selected, 530 °C and 550 °C, respectively, with solution time ranging from 2 to 8 h, followed by water quenching and artificial aging at 165 °C with aging time from 2 to 32 h. The results of hardness and tensile tests were correlated with differential scanning calorimetry (DSC) analysis. The best combination of mechanical properties and heat treatment duration was obtained with 2 h solutionizing at 550 °C and 8 h aging at 165 °C. DSC analysis showed that the alloy's mechanical properties reach the maximum value when the β″ phase is completely developed during the artificial aging.

Influence of Applied Load on Abrasive Wear Depth of Hybrid Gr/SiC/Al–Mg–Si Composites in a Two-Body Condition

The influence of load applied on wear depth of stir cast hybrid Gr/SiC/Al 6082 composites in a two-body abrasion was investigated in as cast (AC) and T6 heat-treated condition (T6). The obtained results were compared with its unreinforced alloy and SiC/Al 6082 composites. The parameters of the applied load (5–15 N), grit size (100 μm and 200 μm), and sliding distance of 75 m were used in this study. At 200-μm grit size, the wear depth of hybrid composites with respect to unreinforced matrix alloy was reduced by 38.1% (at 5 N load) and 16.2% (at 15 N load) in AC condition; 25.1% (at 5 N load), and 27% (at 15 N load) in T6 condition. The wear mechanisms were demonstrated through the analysis of wear surfaces.

Effect of Bifilm Oxides on the Dry Sliding Wear Behavior of Fe-Rich Al–Si Alloys

The effect of bifilm oxides on the dry sliding wear behavior of Fe-rich (1.5 wt.%) F332 Al–Si alloy under as-cast and T6 heat-treated conditions was investigated. Toward this end, the surface oxides were intentionally incorporated into the molten alloy by surface agitation. The results showed that, after sliding under the applied load of 75 N, due to the presence of bifilms, the wear rate of base (0.2 wt.% Fe) and 1.5 wt.% Fe-containing alloys increased by almost 22% and 14%, respectively. The results also indicated that, despite the positive effect on the hardness, T6 heat treatment adversely affected the wear resistance of alloys made under surface turbulence condition. This negative effect can be attributed to the expansion of bifilms which, during heat treatment, are converted to the potential sites for initiation and propagation of subsurface microcracks. However, the strengthening effect exerted by the thermally modified β-Al5FeSi platelets showed that it can compensate the negative effects of bifilm oxides because it improves the wear rate of 1.5 wt.% Fe-containing F332-T6 alloy by about 5% under the applied load of 75 N.

Microstructural and mechanical features of aluminium semi-solid alloys made by rheocasting technique

The rheocasting process applied by Swirled Enthalpy Equilibration Device (SEED) technique relies on rapid extraction of a controlled quantity of heat from the liquid aluminium alloy via mechanical agitation to form the semi-solid slurry that can be formed under pressure. Microstructural characteristics of both conventional and semi-solid A357 castings under T6 heat treatment conditions were examined using optical and scanning electron microscopy. The fatigue and tensile experiments were applied to evaluate the effect of SEED technique on the mechanical properties of T6-A357 semi-solid alloys and conventional castings. The results showed that the rheocasting–SEED technique has proved successful in producing optimum microstructure of Al–Si–Mg semi-solid alloys providing an excellent combination of quality and mechanical performance as compared to conventional technique.This paper is part of a Themed Issue on Aluminium-based materials: processing, microstructure, properties, and recycling.

Correlation between Aging Effects and High Temperature Mechanical Properties of the Unmodified A356 Foundry Aluminium Alloy

In this study, the effect of aging on the mechanical properties of unmodified A356 aluminium casting alloy with trace additions of Ni or V was investigated. Trace elements were added in concentrations of 600 and 1000 ppm of Ni and V, respectively. Samples from sand and permanent mould castings in as cast and T6 heat-treated conditions were tested. Tensile tests were performed at both room and high temperature (235 °C). Taking into account the results from both testing conditions, Vickers hardness was measured in order to endorse the hypothesis of artificial aging occurring during high temperature tensile tests. In order to study this effect, a series of specimens was aged at 235 °C for different aging times, and aging curves were plotted. The occurrence of static and dynamic aging was evaluated by comparing hardness values of tensile specimens and aged samples, particularly in the range of 5-20 min, as this range corresponds to the time necessary for pre-heating and testing of the tensile samples. A basic correlation between tensile strength and hardness is also given.

Mechanical and tribological properties of AA7075–TiC metal matrix composites under heat treated (T6) and cast conditions

The sliding friction and wear behavior of aluminum matrix composites (AA7075–TiC) have been investigated under dry sliding wear conditions. The aluminum metal matrix composites (AMMCs) are produced as AA7075 matrix metal and TiC particulates of an average size of 2μm as reinforced particles through stir casting. AMMCs studied are contained 2–10wt.% of TiC particles in both as cast and heat treated (T6) conditions. All the composites exhibited better mechanical properties (hardness, tensile strength and percentage of elongation) than the matrix metal in both the conditions. The wear tests were carried out at a sliding velocity of 2m/s, sliding distance 2km and at normal load of 20N. The wear resistance of the composites increased with increasing weight percentage of TiC particles, and also the wear rate was notably less for the composite material compared to the matrix material. A detailed analysis in as-cast condition and T6 condition of the AMMCs was carried out using SEM in order to find out the influence of TiC particles in the AMMCs formed. It has been observed that under T6 heat treatment condition, matrix as well as composite shown significant improvement in mechanical and tribological properties when compared in as cast condition.

Materials Performance and Design Analysis of Suspension Lower-Arm Fabricated from Al-Si-Mg Castings

The diversity of physical and mechanical properties of aluminum alloys leads to develop a variety of manufacturing processes including the semi-solid casting process. Fatigue failure is considered the most common problem occurred in automotive engineering applications by which the vehicle components, mainly suspension system parts, fail under conditions of dynamic loading. It is well known that the fatigue life of aluminum castings, mainly A357, is very sensitive to casting design as well as to casting defects and microstructure constituents. The fatigue characteristics of automotive lower suspension arm made of semi-solid A357 aluminum castings have been investigated using metallurgical and analytical approaches. The critical stress areas capable of initiating cracks during fatigue tests are detected by using fatigue experimental design for real part materials by the installation of strain gages on the suspension arm to calculate maximum stress; further more, analytical approach is applied using modelling software. Microstructure characteristics of the semisolid A357 under T6 heat treatment conditions are examined using scanning electron microscope. The results show that using the SEED casting technology (Swirled Enthalpy Equilibration Device) has an efficient effect on the mechanical and metallurgical characteristics of real part materials that are also affected by castings design.

Influence of Heat Treatment on Microstructure and Mechanical Properties of Rare Earth-Rich Magnesium Alloy

The experimental activity was aimed at optimizing the T6 heat treatment conditions of the innovative rare earth-rich magnesium alloy EV31A (Elektron 21®). The investigated alloy (Mg–Nd2.8–Gd1.5–Zr0.5–Zn0.2) contains Nd and Gd in proper amounts to maximize both castability and high-temperature performance. The effect of treatment parameters on microstructure, hardness and tensile properties was evaluated. Mg12NdxGd(1−x) ternary eutectic, Zr clusters and Mg/Nd–Gd intermetallic compounds were found in the as-cast alloy. A remarkable microstructural evolution, involving Mg/Nd–Gd compounds dissolution, was observed in the aged alloy; the precipitation sequence was identified as βII → βI → β. DTA analyses confirmed that 793 K (520 °C/968 °F) is the optimum solutionizing temperature in order to avoid incipient melting; on the contrary, the solutionizing time, should be reduced with respect to the standard conditions without loss in the final alloy hardness and tensile properties. The effect of aging parameters was also investigated at fixed solutionizing and quenching conditions; different aging temperatures [463, 473, 483 K (190, 200, 210 °C/374, 392, 410 °F)] and aging times (up to 48 h) were studied. The aging curves at 463 K (190 °C/374 °F) and 473 K (200 °C/392 °F) showed a similar trend, with a large peak-aging plateau; on the contrary, the peak-aging time was significantly reduced at 483 K (210 °C/410 °F). Tensile tests, performed on the most promising heat treatment conditions, did not show remarkable differences in terms of yield, ultimate tensile strength and elongation to failure with respect to the standard heat treatments conditions. This study therefore suggests that standard solutionizing and aging times can be considerably shortened, ensuring excellent mechanical properties, compared to standard T6 heat treatment, leading to commercial implications with regard to operational costs and energy saving.

AC2BS합금의 열간 균열강도 및 인장특성에 미치는 스크랩 함량의 영향

The effects of scrap content on the hot tearing property and tensile property were investigated in AC2BS alloy. The hot tearing strengths were <TEX>$16.4kgf/cm^2$</TEX>, <TEX>$15.2kgf/cm^2$</TEX>, <TEX>$14.9kgf/cm^2$</TEX> and <TEX>$13.3kgf/cm^2$</TEX>, respectively, under the constant solid fraction of 29.3% when the scrap contents of the specimens were 0%, 20%, 35% and 50%. In the same way, tensile strengths of the as-cast condition were <TEX>$24.5kgf/mm^2$</TEX>, <TEX>$23.7kgf/mm^2$</TEX>, <TEX>$17.3kgf/mm^2$</TEX> and <TEX>$16.0kgf/mm^2$</TEX>, respectively, and the corresponding tensile strengths of the T6 heat treatment condition were <TEX>$27.2kgf/mm^2$</TEX>, <TEX>$26.7kgf/mm^2$</TEX>, <TEX>$24.2kgf/mm^2$</TEX> and <TEX>$23.9kgf/mm^2$</TEX>. Hot tearing strength and tensile strength decreased as scrap content of the specimen increased. According to the evaluation of the quantitative hot tearing and tensile test results, the decrease of these strengths is due to the presence of oxide films which act as crack initiation site of the specimens. Therefore, elimination of oxide films of aluminum melt to maintain melt cleanliness is required.

Effect of Cr, Ti, V, and Zr Micro-additions on Microstructure and Mechanical Properties of the Al-Si-Cu-Mg Cast Alloy

Uniaxial static and cyclic tests were used to assess the role of Cr, Ti, V, and Zr additions on properties of the Al-7Si-1Cu-0.5Mg (wt pct) alloy in as-cast and T6 heat-treated conditions. The microstructure of the as-cast alloy consisted of α-Al, eutectic Si, and Cu-, Mg-, and Fe-rich phases Al2.1Cu, Al8.5Si2.4Cu, Al5.2CuMg4Si5.1, and Al14Si7.1FeMg3.3. In addition, the micro-sized Cr/Zr/Ti/V-rich phases Al10.7SiTi3.6, Al6.7Si1.2TiZr1.8, Al21.4Si3.4Ti4.7VZr1.8, Al18.5Si7.3Cr2.6V, Al7.9Si8.5Cr6.8V4.1Ti, Al6.3Si23.2FeCr9.2V1.6Ti1.3, Al92.2Si16.7Fe7.6Cr8.3V1.8, and Al8.2Si30.1Fe1.6Cr18.8V3.3Ti2.9Zr were present. During solution treatment, Cu-rich phases were completely dissolved, while the eutectic silicon, Fe-, and Cr/Zr/Ti/V-rich intermetallics experienced only partial dissolution. Micro-additions of Cr, Zr, Ti, and V positively affected the alloy strength. The modified alloy in the T6 temper during uniaxial tensile tests exhibited yield strength of 289 MPa and ultimate tensile strength of 342 MPa, being significantly higher than that for the Al-Si-Cu-Mg base. Besides, the cyclic yield stress of the modified alloy in the T6 state increased by 23 pct over that of the base alloy. The fatigue life of the modified alloy was substantially longer than that of the base alloy tested using the same parameters. The role of Cr, Ti, V, and Zr containing phases in controlling the alloy fracture during static and cyclic loading is discussed.

The Influence of Ni and V Trace Elements on High-Temperature Tensile Properties and Aging of A356 Aluminum Foundry Alloy

High-temperature tensile properties of unmodified A356 alloy with and without the addition of Ni or V in traces (600 and 1000 ppm of Ni and V, respectively) were investigated by analyzing samples obtained from sand and permanent mold castings in the as-cast and T6 heat-treated conditions. Tensile tests were performed at 508 K (235 °C) at a crosshead speed of 1 mm/min. In addition, samples were subjected to artificial aging at 508 K (235 °C) for different times, and corresponding hardness curves were plotted. Microstructures and fracture surfaces, analyzed by FEG-SEM equipped with energy dispersive X-ray spectroscopy, showed that neither Ni nor V addition had a detrimental effect on high-temperature tensile properties. Aging curves showed a strong loss of hardness affecting the T6 class between 30-min and 1-h exposure time. After 6-h aging, no evidence of aging treatment persisted on hardness of the tested material. Hardness values did not reveal any significant difference between the reference alloy and the Ni- and V-containing alloys in both casting conditions, in complete analogy with the tensile properties. Unmodified eutectic silicon particles provided inhomogeneity in the α-Al matrix and acted as the principal source of stress concentration leading to fracture.

Effect of transition metals on energy absorption during strain-controlled fatigue of an aluminum alloy

Tensile and low cyclic fatigue tests were used to assess the influence of micro-additions of Ti/V/Zr on the performance of Al–7Si–1Cu–0.5Mg (wt.%) alloys in the as-cast and T6 heat-treated conditions and their improvement was compared to the base alloy. The microstructure of the as-cast Al–7Si–1Cu–0.5Mg (wt.%) base and modified alloys consisted of α-Al, eutectic Si, and Cu, the Mg- and Fe-based phases Al2.1Cu, Al8.5Si2.4Cu, Al7.2Si8.3Cu2Mg6.9 and Al14Si7.1FeMg3.3. In addition, the micro-sized Ti/V/Zr-rich phases Al6.8Si1.4Ti, Al21.4Si4.1Ti3.5VZr3.9, Al6.7Si1.2TiZr1.8, Al2.8Si3.8V1.6Zr and Al5.1Si35.4Ti1.6Zr5.7Fe were identified in the modified alloys. It was also noticed that increasing the content of Ti–V–Zr changed the morphology of Ti/V/Zr-rich phase. The tensile test results showed that the T6 heat-treated alloy modified with the addition of a higher content of Ti–V–Zr achieved the highest tensile strength of 343MPa over the base alloy and alloys modified with additions of Ti, Ti–Zr and lower contents of Ti–V–Zr. The plastic strain energy density coefficient of the alloy modified with the addition of a higher content of Ti–V–Zr in the T6 temper condition was higher than the other studied alloys and reached 162MJm−3. The fatigue life of the same alloy was considerably longer than that of the other studied alloys, including the base alloy. The fractography revealed that all the studied alloys showed similar fracture behavior. The tensile cracks propagated through the eutectic Si and primary phases, exhibiting intergranular fracture along with some cleavage-like features of the plate-shaped Zr–Ti–V-rich intermetallics with the presence of fatigue striations on the latter, indicating their ductile nature. It is believed that the morphological changes of intermetallic precipitates containing Zr, Ti and V enhance the fatigue life of the alloy modified with additions of larger amounts of Ti–V–Zr in the T6 condition.

Low Cycle Fatigue Life Prediction of Al–Si–Mg Alloy Using Artificial Neural Network Approach

The aim of this investigation is to develop a model to predict low cycle fatigue (LCF) life of Al–Si–Mg based alloys and establish a correlation between some important processing parameters and LCF life of the investigated alloy. A most popular statistical analysis tool known as artificial neural network model based on multilayer feedforward neural network has been used in this prediction approach. For accurate prediction of fatigue life, a large dataset has been created by collecting the input–output pairs of the experimental results from existing literature. The effects of various processing parameters such as Si content, Mg content, heat treatments, etc. on LCF life have also been predicted using the created network. The predicted results indicate that the fatigue life increases with increase in both Si and Mg content in the alloy; the results are in accordance with some experimental observations available in literature. It is also predicted that fatigue life, which increases with decreasing strain amplitude, was shifted towards the higher number of cycles to failure under T6 heat treatment condition than under both T5 and some modified T6 heat treatment conditions. Similar conclusions are also drawn for experimental results as reported in some literature. The life predictive capability of the created network shows a good acceptability as most of the predicted results lies within a factor of 2.

Fatigue Characteristics and Quality Index of A357 Type Semi-Solid Aluminum Castings Used for Automotive Application

The present work aims to investigate the fatigue characteristics of automotive lower suspension arm made of semi-solid A357 aluminum castings using metallurgical and analytical approaches. The fatigue life calculations of analytical model are used to identify and introduce the model parameters based on the suspension arm material followed by analyzing the load-number of cycles fatigue curve. The critical stress areas capable of initiating cracks during fatigue tests are detected using ABAQUS software followed by the installation of strain gages on the suspension arm to calculate maximum stress. The fatigue experiments are carried out to compare the results of the analytical method with the experimental endurance curves traced by lower suspension arm samples. Microstructure characteristics of the semi-solid A357 under T6 heat treatment conditions are examined using scanning electron microscope. The results show that the fatigue life and the quality index of alloys investigated are affected by casting technique, castings design, microstructural characterization, and heat treatment condition.

Impact Behavior of A356 Foundry Alloys in the Presence of Trace Elements Ni and V

In the present work, the impact behavior of unmodified A356 alloys with the addition of Ni or V in as-cast and T6 heat-treated conditions was assessed. Charpy V-notched specimens obtained from sand and permanent mold casting showed low total absorbed energy average values (Wt < 2 J). SEM analysis of fracture profiles and surfaces indicated a Si-driven crack propagation with a predominant transgranular fracture mode. Occasionally, intergranular contributions to fracture were detected in the permanent mold cast alloys due to the locally finer microstructure. Concurrent mechanisms related to the chemical composition, solidification conditions and heat treatment were found to control the impact properties of the alloys. While the trace element Ni exerted only minor effects on the impact toughness of the A356 alloy, V had a strong influence: (i) V-containing sand cast alloys absorbed slightly higher impact energies compared to the corresponding A356 base alloys; (ii) in the permanent mold cast alloys, V in solid solution led to a considerable loss of ductility, which in turn decreased the total absorbed energy.

Low cycle fatigue of SiCp reinforced AA2009 composites

Abstract Strain-controlled low cycle fatigue (LCF) characteristics of an extruded Al–Cu–Mg aluminum alloy reinforced with SiC particles (SiCp/AA2009 composite) in the T4 and T6 heat treatment conditions were investigated. In comparison with the T6 condition with Al 2 CuMg precipitates, the composite in the T4 condition had a higher ductility and equivalent ultimate tensile strength despite a lower yield strength, leading to a higher strain hardening exponent and hardening capacity. Unlike the extruded magnesium alloys, the SiCp/AA2009 composite exhibited symmetrical hysteresis loops in tension and compression due to the dislocation slip-dominated deformation in the aluminum matrix. Cyclic hardening occurred at higher strain amplitudes with a more pronounced hardening in the T4 condition, and cyclic stabilization remained at lower strain amplitudes (0.1–0.3%). Fatigue life in both conditions was equivalent, which can be well described by the Coffin–Manson law and Basquin’s equation. Strain ratio significantly affected cyclic deformation characteristics of the composites in both conditions, with a large amount of plastic deformation observed in the tensile phase of the first cycle of hysteresis loops at zero or positive strain ratios. A mean stress relaxation was observed. Fatigue crack was observed to initiate from the specimen surface and crack propagation was characterized predominantly by particle cracking along with de-bonding.

Evaluating porthole and seamless aluminum tubes and lubricants for hydroforming

The effect of extrusion method and lubrication on formability of aluminum tubes in hydroforming is experimentally investigated. First, the formability differences between seamless and porthole aluminum 6063 and 6260 alloy tubes, at T1 and T6 heat treatment conditions, are studied using free bulging. Second, the performances of a wide range of lubricants are ranked using zone-dependent friction tests, e.g., guiding zone and expansion zone, which emulate the two different interface mechanics existing in a THF operation. Results showed that seamless tubes, under any condition, give 5 % more expansion compared to porthole. Also, if a tube has T6 condition, seamless shows clear formability advantage over porthole. However, porthole is found to be quite satisfactory for tubes at T1 condition since they achieved more than %10 expansion. “Zone-dependent” (expansion zone and guiding zone) lubrication tests are conducted using wet and dry lubricants. Results showed that while a dry lubricant performed best in the expansion zone, a wet lubricant performed best in the guiding zone.