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研究不同烧结方法,包括放电等离子体烧结(SPS)、热压(HP)和电阻烧结(ERS),对商用纯钛(CP-Ti)粉末固结后显微组织和力学性能的影响。选用的粉末粒度分别为<147μm,<74μm和<43μm,粉末粒度越小,其致密化过程越快。在850°C、30 MPa条件下进行SPS和HP,获得烧结体的相对密度高达99%。而通过ERS,则在950°C、30 MPa条件下才发生CP-Ti粉末的致密化。在850~950°C获得烧结钛的显微组织由等轴晶构成。对于粒度<43μm粉末,在850°C、30 MPa条件下通过SPS制备烧结体,其屈服强度为868 MPa。随着小尺寸颗粒含量的升高,通过SPS和HP制备烧结体的屈服强度得到提高。然而在950°C、30MPa条件下,通过ERS制备样品的最高屈服强度仅为441 MPa,比SPS和HP样品的低。与SPS和HP相比,ERS需要较短的烧结时间,但较高的烧结温度导致材料的脆性断裂,使其强度和伸长率降低。
The effects of various sintering methods including SPS, HP and ERS on the microstructure and mechanical properties of commercial pure titanium (CP-Ti) powders were investigated. The selected powder particle sizes were <147μm, <74μm and <43μm, the smaller the particle size of the powder, the faster the densification process. SPS and HP were performed at 850 ° C and 30 MPa to obtain a sintered body with a relative density of up to 99%. With ERS, densification of the CP-Ti powder occurs at 950 ° C and 30 MPa. The microstructure of sintered titanium obtained at 850-950 ° C consists of equiaxed grains. For powders with a particle size of <43 μm, the sintered body was prepared by SPS at 850 ° C, 30 MPa with a yield strength of 868 MPa. As the content of small size particles increases, the yield strength of the sintered body prepared by SPS and HP is increased. However, at 950 ° C and 30 MPa, the highest yield strength of samples prepared by ERS was only 441 MPa, which was lower than that of SPS and HP samples. ERS requires a shorter sintering time than SPS and HP, but a higher sintering temperature results in a brittle fracture of the material, resulting in a decrease in strength and elongation.