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Abstract A strong and ductile Mg-8Al-1Zn-1Ca-0.3Mn (wt%) alloy sheet has been successfully developed via commercial rolling process. The ultimate tensile strength, 0.2% proof stress, and elongation to failure along the rolling direction of the sheet are 371 MPa, 275 MPa, and 17.1%, respectively. The high strength and ductility are attributed to the fine recrystallized grains and densely dispersed fine Mg 17 Al 12 precipitates. Further, due to its isotropic basal texture, the Mg-8Al-1Zn-1Ca-0.3Mn alloy sheet shows little in-plane anisotropy. The ultimate tensile strength, 0.2% proof stress, and elongation to failure along the 45° and transverse direction of the sheet are almost the same as those in the rolling direction. The good tensile properties can be realized by using only inexpensive ingredients and commercial rolling process; therefore, the Mg-8Al-1Zn-1Ca-0.3Mn alloy sheet will be a candidate as structural materials for transportation vehicles. [ABSTRACT FROM AUTHOR]

Mg–1.3Al–0.8Zn–0.7Mn–0.5Ca (wt.%) (AZMX1110) alloy sheet produced by low-cost twin-roll casting process exhibits excellent room temperature formability with a large Index Erichsen (I.E.) value of 7.8 mm at room temperature in a solution treated condition (T4). The large I.E. value is associated with a weak basal texture in the T4-condition. This alloy shows rapid age-hardening response at 170 °C, resulting in a significant increase of the flow stress from 198 MPa to 238 MPa within 20 min; such bake hardenability (BH) has never been explored in magnesium sheet alloys before. The microstructure of the bake-hardened sample, characterized by a correlative transmission electron microscopy and atom probe tomography (TEM-APT), reveals that Al, Zn and Ca atoms are segregated to basal dislocations and contribute to the strengthening by pinning dislocation motions, along with the co-clustering of these atoms. This first BH Mg sheet alloy composed of only ubiquitous elements is highly attractive for application to automotive bodies. [ABSTRACT FROM AUTHOR]

We clarified the role of Zn on the mechanical properties and texture evolution in Mg-1.2Al-0.5Ca-0.4Mn- x Zn (wt.%, x = 0, 0.8 and 1.6) alloy sheets fabricated by twin-roll casting and hot rolling. The room temperature stretch formability of the solution-treated sheet is improved with increasing Zn content, x. The Mg-1.2Al-0.5Ca-0.4Mn-1.6Zn alloy shows excellent stretch formability with the largest Index Erichsen value of 8.2 mm due to a weak transverse direction split texture. The development of the transverse direction split texture is attributed to the preferential nucleation of recrystallized grains at double twin boundaries promoted by the moderate segregation of Zn and Al. Subsequent artificial aging at 170 °C for 2 h (T6) leads to a substantial increase in strength without loss of ductility. The peak-aged Mg-1.2Al-0.5Ca-0.4Mn-1.6Zn alloy exhibits a high tensile yield stress of 210 MPa with an excellent elongation of 30.1% because of the dense dispersion of Guinier Preston zones within the Mg matrix. The insights gained in this work would establish a base for rational design and fabrication of bake-hardenable magnesium alloy sheet with excellent room temperature formability and high strength. Image 1 • This work established a base to design strong and formable magnesium alloy sheets. • The Zn addition is effective to achieve excellent room temperature formability. • The Zn addition changes recrystallization mechanism during the heat treatment. • The addition of Zn increases the number density of G.P. zone formed during aging. [ABSTRACT FROM AUTHOR]

During laparoscopic surgery, surgeons observe the three-dimensional abdominal cavity on a two-dimensional TV monitor, which is a limitation. Another limitation is that surgeons are unable to estimate the softness of organs or tissues during laparoscopic surgery as they are only allowed to use instruments which touch objects and direct palpation is not permitted during the procedure. The tactile sensor which we used displays the object softness immediately as a digital score, which can then be superimposed on a TV monitor as a graph. With the tactile sensor, we were able to ascertain the presence of a gallstone in the gallbladder or cholecystic duct during laparoscopic cholecystectomy and also able to discriminate between a stone and an air bubble during intraoperative cholangiography. We were convinced that the tactile sensor would be useful in laparoscopic surgery, which does not permit surgeons to palpate objects with human fingers. [ABSTRACT FROM AUTHOR]