The results show that the upsetting deformation law of sintered preform is alike with the compact body, and the crank press is the best equipment of powder forging technology.
结果表明：烧结体的镦粗变形规律与致密体相同。指出了曲柄压力机是粉末锻造工艺的最佳设备。
2
The preform is formed by an upper neck which maintains unchanged its form in the final object and a hollow body, joined to the neck.