33results about How to "Change phase transition temperature" patented technology

The invention provides a rare earth magnetic material with magnetic field controlled deformation and a preparation method thereof, and belongs to the field of shape memory materials.The material has the ability of producing micro deformation under the control of an external magnetic field at indoor temperature or higher temperature.The rare earth magnetic material is the novel rare earth magnetic control shape memory alloy capable of producing stress when martensite twin boundaries are driven by external magnetic field changes at indoor temperature or higher temperature.The chemical formula of the alloy is CoxNiyALzTbj, wherein x is larger than or equal to 27 and is smaller than or equal to 45, y is larger than or equal to 20 and is smaller than or equal to 31, z is larger than or equal to 20 and is smaller than or equal to 34, j is larger than or equal to 0.5 and is smaller than or equal to 8, the sum of x, y, z and j is 100, and x, y, z and j represent mole percentage content.Compared with existing materials, the rare earth magnetic material has the wide field-induced strain range, large field-induced strain and good mechanical property, and has the important application in the fields of micro displacement devices, vibration and noise control, linear motors, microwave devices, robots and the like capable of being used at the temperature higher than indoor temperature.

The invention discloses a Ti-Nb-O memory alloy having a high recoverable strain and a preparation method thereof. The method comprises the steps: mixing uniformly a pure Ti powder, a pure Nb powder, a pure TiO2 powder and a pure TiH2 powder according to the ratio of Ti atoms, Nb atoms, O atoms and H atoms being (77-91):(8-18):(1-3):(0-5), and carrying out compression molding to obtain a green body; putting the green body into a sintering furnace, sintering under a protective gas atmosphere, and thus obtaining a sintered-state Ti-Nb-O alloy; putting the Ti-Nb-O alloy into a tube furnace, carrying out solid solution treatment under the argon gas protection, putting the solid solution state Ti-Nb-O memory alloy into the tube furnace, carrying out aging treatment under the argon gas protection, and then rapidly cooling in ice water to obtain the high recoverable strain. The Ti-Nb-O alloy shows low elastic modulus, extremely high compressive strength and relatively high recoverable strain, and is suitable for use in medical hard tissue replacement and reparation materials.

The invention provides a rare earth magnetic-control shape memory alloy low in starting critical stress and a preparation method thereof and belongs to the field of memory alloy materials. The material has the capacity to generate deformation under the control of a weak external magnetic field under the indoor temperature condition and is novel rare earth magnetic-control shape memory alloy according to which strain can be generated due to martensite twin boundary migration under the driving of the external magnetic field change with small strength at the indoor temperature. The chemical formula of the alloy is CoxNiyAlzCej, wherein 18<=x<=43, 27<=y<=34, 26<=z<=40, 1<=j<=15, x+y+z+j=100, and x, y, z and j represent the molar percentages. Compared with existing materials, the rare earth magnetic material has the low martensite twin crystal migration starting critical stress, wide magnetic-induced strain temperature range, high magnetic-induced strain capacity and good mechanical property and has important application value in the fields of micro displacement machines used at the indoor temperature, vibrating and noise control, linear motors, microwave devices, robots and the like.

The invention discloses a Ni-Fe-Al alloy with linear superelasticity and a preparation method thereof. The composition and content (by atomic percentage) of the alloy are: nickel (Ni) is 56.5-51%, iron (Fe) It is 18.5-22%, and the rest is aluminum (Al). The Ni-Fe-Al alloy is directly prepared by powder metallurgy technology, and the process includes mixing, pressing, sintering and heat treatment (quenching). The alloy sintered billet exhibits linear superelasticity after quenching treatment, and the elastic recovery is 3-7%. The invention has a wide range of applications. In actual engineering, the superelasticity can be used to absorb and dissipate the vibration energy of the structure. It can be used to make mechanical sensing and control elements, human body orthopedic elements, damping elements, high-efficiency elastic elements, and wave absorbing and reducing elements. Shock and noise prevention devices, overload protection monitoring and forecasting of structural parts.