公开(公告)号：US11673196B2

公开(公告)日：2023-06-13

申请号：US16793897

申请日：2020-02-18

Applicant: UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING

Inventor： Lin Zhang ,  Xuanhui Qu ,  Xingyu Li ,  Mingli Qin ,  Yanhao Dong ,  Ju Li ,  Guanghua Wang ,  Ying Long ,  Wei Zhong

IPC: B22F3/16 ,  B22F9/02 ,  B22F1/05 ,  B22F1/10 ,  B22F1/065 ,  B22F1/142 ,  B22F9/04

CPC classification number: B22F3/16 ,  B22F1/05 ,  B22F1/065 ,  B22F1/10 ,  B22F1/142 ,  B22F9/026 ,  B22F2009/041 ,  B22F2201/013 ,  B22F2201/11 ,  B22F2203/11 ,  B22F2203/13 ,  B22F2301/20 ,  B22F2998/10

Abstract: A method to achieve full densification and grain size control for sintering metal materials, wherein raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

公开(公告)号：US11852209B2

公开(公告)日：2023-12-26

申请号：US16793938

申请日：2020-02-18

Applicant: UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING ,  BEIJING TIANYISHANGJIA NEW MATERIAL CORP., LTD.

Inventor： Lin Zhang ,  Xuanhui Qu ,  Peng Zhang ,  Peifang Wu ,  Mingli Qin ,  Cairang Shijia ,  Jingwu Cao ,  Kangxi Fu

IPC: F16D69/02 ,  B22F3/16 ,  B22F7/00 ,  C22C47/14 ,  C22C49/02 ,  C22C49/14 ,  F16D65/092 ,  G01N19/02 ,  B22F1/10

CPC classification number: F16D69/028 ,  B22F1/10 ,  B22F1/108 ,  B22F3/16 ,  B22F7/008 ,  C22C47/14 ,  C22C49/02 ,  C22C49/14 ,  F16D65/092 ,  G01N19/02 ,  B22F2301/10 ,  B22F2302/40 ,  B22F2304/10 ,  F16D2200/0008 ,  F16D2200/0026 ,  F16D2200/0052 ,  F16D2200/0065 ,  B22F2998/10 ,  B22F1/108 ,  B22F3/14 ,  B22F2003/023

Abstract: The present disclosure relates to a fiber-reinforced copper-based brake pad for high-speed railway train, and preparation and friction braking performance thereof. The fiber-reinforced copper-based brake pad for high-speed railway train comprises 80-98.5 wt. % metal powder, 1-15 wt. % non-metal powder and 0.5-5 wt. % fiber component. In addition, some components are added in a specific proportion to achieve optimal performance. The copper-based powder metallurgy brake pad is obtained by powder mixing, cold-pressing and sintering with constant pressure. The friction braking performance of the obtained brake pad is tested according to a braking procedure consisting of three stages, i.e., the first stage with low-pressure and low-speed, the second stage with high-pressure high-speed and the continuous emergency braking third stage with high-pressure and high-speed. The brake pad has advantages including higher and more stable friction coefficient, higher fade and wear resistance and slighter damage to brake disc at high speeds.

公开(公告)号：US11618085B2

公开(公告)日：2023-04-04

申请号：US16800688

申请日：2020-02-25

Applicant: UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING

Inventor： Baicheng Zhang ,  Lin Zhang ,  Shubin Ren ,  Mingli Qin ,  Xuanhui Qu

IPC: B33Y30/00 ,  B22F12/58 ,  B22F12/67 ,  B22F10/28 ,  B22F12/49 ,  B22F10/14

Abstract: A selective laser melting technology-based apparatus for preparing a gradient material, comprising a laser scanning array lens, and a powder storer, a powder mixer, a powder scraping plate, and a working platform that are provided in sequence from top to bottom; the powder storer is provided with two or more partitions; a bottom portion of the powder storer is provided with an outlet; the powder mixer is provided under the powder storer and is a horizontally provided rotational mixer; the powder scraping plate is disposed under the powder mixer; the working platform is provided under the powder scraping plate; the laser scanning array lens is provided on the working platform. The present invention further relates to a method for preparing a gradient material, comprising powder storing, powder scraping, powder mixing, powder laying, and printing. The method can guarantee the two-phase powder ratio in each layer of powder not change.