4 results about "Back stress" patented technology

Ceramic honeycomb bodies and methods for their manufacture are provided. The ceramic honeycomb body comprises a bulk density of less than 210 g / L, a geometric surface area (GSA) greater than 93 in−1 (3.66 mm−1), a mechanical integrity factor (MIF) greater than 0.28%, and a back pressure factor (BPF) greater than 0.4 mm2.

This invention relates to the field of medium-high entropy alloy technology, specifically to a high-strength and high-toughness multi-level heterogeneous medium-entropy alloy and its preparation method. This invention discloses a CoNiVAlTa-based medium-entropy alloy, which, through compositional design and process adjustment, utilizes low-temperature pre-aging to induce metastable phase transformation, followed by high-temperature recrystallization to achieve grain refinement and precipitation of multi-level strengthening phases. By introducing multiple strengthening mechanisms—grain refinement strengthening, precipitation strengthening, and back stress strengthening—the material possesses both high strength and high plasticity. This series of alloys exhibits a tensile strength of 1460 MPa to 1615 MPa at room temperature and a fracture elongation of 15% to 27%. This high-strength and high-toughness multi-level heterogeneous medium-entropy alloy not only boasts excellent comprehensive mechanical properties but also features a simple and feasible process, demonstrating great promise for engineering applications.

The present application relates to a kind of fastening process fastening effect evaluation method considering internal stress, comprising: simulating the fastening process to be evaluated, fastening, unloading and reverse fastening are carried out to fastener sample, and the stress and strain of different time are obtained;Multiple stress and strain points in stress and strain coordinate system are obtained;According to the multiple stress and strain points of unloading and reverse fastening process, the elastic segment region of unloading and reverse fastening process is obtained;The maximum stress and minimum stress of each stress and strain point in the elastic segment region are obtained, respectively as the upper limit of elastic segment and the lower limit of elastic segment;The back stress of fastener sample is determined;According to the back stress of fastener sample, the fastening effect evaluation result of the fastening process to be evaluated is obtained.The fastening process fastening effect evaluation method considering internal stress of the present application uses the back stress of fastener sample to evaluate fastening effect, so as to consider the influence of fastening process on fastening effect, to accurately assess the fastening effect of fastener.

The utility model discloses a band sawing machine back pressure mechanism, including base, setting in the stand of base, the sawing frame of lifting slide setting in the stand and the lifting assembly of driving sawing frame to lift, the lifting assembly includes the ball screw, still includes back pressure support subassembly, back pressure support subassembly does not interfere with sawing frame movement and always provides the upward supporting force to sawing frame. The utility model has the advantages and effects that: through the back pressure support spare of setting to provide the upward supporting force to sawing frame, then alleviates the gravity of sawing frame up and down, in this way to share the stress on the ball screw, then prolongs the service life of ball screw, to reduce the maintenance cost of equipment later period.